EXHIBIT 10.1
















                                        LEASE

                                    by and between

                              NDNE 9/90 Corporate Center LLC
                                     or assignee

                                    as Landlord and

                            AQUILA BIOPHARMACEUTICALS, INC., 

                                      as Tenant





                             Dated as of September 19, 1997 
                             with an effective date as of the
         "
                                 Escrow Release Date" 
                          (as said term is defined in the Lease)<PAGE>







                            TABLE OF CONTENTS


         SECTION 1 - Reference Data
         1
              Section 1.1 Reference Information .................  
              Section 1.2 Exhibits ..............................  

         SECTION 2 - Premises and Term   7
              Section 2.1 Premises ..............................  
              Section 2.2 Term ..................................  
              Section 2.3 Appurtenant Rights and Reservations....  

         SECTION 3 - Commencement Date; Improvements
         8
              Section 3.1 Commencement Date .....................
              Section 3.2 Construction of Building ..............  
              Section 3.3 Tenant Improvements; Tenant Plans......
                             and Specifications.....................  
              Section 3.4 Tenant Work ...........................  
              Section 3.5 General Provisions Applicable to....... 
                              Tenant Work and Landlord Work.........  
              Section 3.6 Performance of Tenant's Work...........
              Section 3.7 Delays.................................
              Section 3.8 General Provisions Applicable to ......
                              Construction..........................
              Section 3.9 Construction Representations...........
              Section 3.10   Changes in Building or Lot.............

         SECTION 4 - Rent              16
              Section 4.1 The Annual Rent .......................  

         SECTION 5 - Operating Cost Escalation
         16
              Section 5.1 Operating Cost Escalation .............  
              Section 5.2 Estimated Operating Cost...............
                             Escalation Payments ...................  

         SECTION 6 - Real Estate Tax Escalation
         18
              Section 6.1 Real Estate Tax Escalation ............  
              Section 6.2 Estimated Real Estate Tax Escalation...
                             Payments ..............................  
              Section 6.3 Assessment of Property ................

         SECTION 7 - Insurance
         19
              Section 7.1 Tenant's Insurance ....................  
              Section 7.2 Requirements Applicable to Insurance...
                              Policies........................... ..  
              Section 7.3 Waiver of Subrogation .................  

         SECTION 8 - Landlord's Covenants
         21
              Section 8.1 Quiet Enjoyment .......................  
              Section 8.2 Maintenance and Repair ................  
              Section 8.3 Electricity, Water and Gas..............  
              Section 8.4    HVAC.
         .................................. 
              Section 8.5 Cleaning ............................... 
              Section 8.6 Interruptions .......................... 
              Section 8.7 Representations.........................
              Section 8.8 Estoppel Certificates..................<PAGE>






         SECTION 9 - Tenant's Covenants
         24
              Section 9.1 Use ................................... 
              Section 9.2 Repair and Maintenance  ............... 
              Section 9.3 Compliance with Law and Insurance......
                             Requirements .......................... 
              Section 9.4 Tenant's Alterations................... 
              Section 9.5 Indemnity ............................. 
              Section 9.6 Landlord's Right to Enter ............. 
              Section 9.7 Personal Property at Tenant's Risk .... 
              Section 9.8 Yield Up .............................. 
              Section 9.9 Estoppel Certificate .................. 
              Section 9.10   Landlord's Expenses Re Consents ....... 
              Section 9.11   Rules and Regulations ................. 
              Section 9.12   Holding Over .......................... 
              Section 9.13   Assignment and Subletting ............. 
              Section 9.14   Overloading and Nuisance .............. 

         SECTION 10 - Casualty or Taking
         29
              Section 10.1   Termination ........................... 
              Section 10.2   Restoration ........................... 
              Section 10.3   Award ................................. 

         SECTION 11 - Default
         30
              Section 11.1   Events of Default ..................... 
              Section 11.2   Remedies .............................. 
              Section 11.3   Remedies Cumulative ................... 
              Section 11.4   Landlord's Right to Cure Defaults ..... 
              Section 11.5   Effect of Waivers of Default .......... 
              Section 11.6   No Accord and Satisfaction ............ 
              Section 11.7   Interest on Overdue Sums .............. 
              Section 11.8   Costs and Expenses ...................  

         SECTION 12 - Mortgages        32
              Section 12.1   Rights of Mortgage Holders ............ 
              Section 12.2   Lease Subordinate...................... 

         SECTION 13 - Miscellaneous Provisions
         34
              Section 13.1   Notices from One Party to the Other ... 
              Section 13.2   Lease Not to be Recorded;..............
                             Notice of Lease ....................... 
              Section 13.3   Bind and Inure; Limitation of..........
                             Landlord's Liability .................. 
              Section 13.4   Acts of God ........................... 
              Section 13.5   Landlord's Default .................... 
              Section 13.6   Brokerage ............................. 
              Section 13.7   Miscellaneous ......................... 
              Section 13.8   Security Deposit ...................... 
              Section 13.9   Park Common Expenses...................
              Section 13.10  Leasehold Parking Area.................
              Section 13.11  Hazardous Materials....................
              Section 13.12  Landlord's Holdover Contribution.......<PAGE>







                                        LEASE


                                      SECTION 1
                                    Reference Data

         Section 1.1. Reference Information.  Reference in this Lease to
         any of the following shall have the meaning set forth below:

         Date of this Lease: As of September 19, 1997 with an
         effective date as of the "Escrow Release Date" (as said term is
         defined in the Lease) 

         Premises:      That portion (shown as outlined on Exhibit A
                        attached hereto) of the Building on the Lot
                        known as Lot 8A and to be numbered 175
                        Crossing Boulevard in Framingham,
                        Massachusetts, consisting of approximately
                        35,000 rentable square feet on the first,
                        second and third floors of the Building.

         Landlord:           NDNE 9/90 Corporate Center LLC or
         assignee

         Address of Landlord: c/o National Development of New England
                             2310 Washington Street
                             Newton Lower Falls, Massachusetts 02162

         Tenant:             Aquila Biopharmaceuticals, Inc.

         Address of Tenant:  365 Plantation Street
                             Worcester, Massachusetts  01605

         Landlord's Construction Representative:   Mark L. Paris

         Tenant's Construction Representative:     Thomas H. Kelly 


         Additional Rent:  Any sum or payment designated under this
         Lease as constituting "Additional Rent" including, without
         limitation, payments by Tenant on account of (i) Operating Cost
         Escalation under Section 5, (ii) Real Estate Tax Escalation
         under Section 6 and (iii) Park Common Expenses under Section
         13.9.

         Affiliate:  Any corporation or business entity controlled by,
         controlling or under common control with Tenant.  For this
         purpose, "control" shall mean direct or indirect beneficial
         ownership of 50% or more of the voting stock of, or a 50% or
         greater interest in the income of such corporation or other
         business entity or such other relationship as in fact
         constitutes actual control.

         Annual Base Operating Costs:   $ 495,600.00 ($4.13 x Total
         Number of Rentable Square Feet in the Building) (which excludes
         any costs and expenses associated with cleaning services in the
         Premises which shall be provided by Tenant at Tenant's sole
         cost and expense). <PAGE>






         Annual Base Real Estate Taxes:  $ 300,000.00 ($2.50 x Total
         Number of Rentable Square Feet in the Building)

         Annual Fixed Rent (includes Annual Base Operating Costs and
         Annual Base Real Estate Taxes
              Lease Years 1 - 4 inclusive: $748,300.00 per annum
              Lease Years 5 - 8 inclusive: $800,800.00 per annum
              Lease Years 9 - 12 inclusive: $853,300.00 per annum


         As used above, the term "Year" or "Lease Year" shall mean the
         one year period ending on the first anniversary of the Term
         Commencement Date and each period of like duration thereafter.

         Annual Rent:  Annual Fixed Rent, Additional Rent and any other
         charge payable in accordance with the terms and provisions of
         this Lease.

         Anticipated Term Commencement Date:  July 1, 1998.

         Base Building:  The building erected or to be erected on the
         Lot by Landlord in accordance with Exhibit D attached hereto at
         such time as Landlord substantially completes "Landlord's
         Building Construction Work", as defined in Section 3.2.

         Broker:  Fallon, Hines & O'Connor, Inc.

         Building:  The building erected or to be erected on the Lot by
         Landlord and all alterations and additions thereto and
         replacements thereof as described in Exhibit D.

         Business Day:  All days except Sundays and legal holidays.

         Business Hours:  7:00 a.m. to 6:00 p.m. on all Business Days
         except Saturdays and Sundays from 8:00 a.m. to 1:00 p.m.

         Commencement Date:  As defined in Section 3.1.

         Enclosed Building:  When the building has reached a state of
         construction such that it is enclosed (sufficient to prevent
         water damage from the weather) and has temporary electrical
         power so as to provide Tenant with access to commence Tenant's
         Work on Tenant's Access Date.

         Escrow Agreement:  That certain Escrow Agreement dated as of
         even date herewith by and among Landlord, Tenant and Chicago
         Title Insurance Company.

         Escrow Release Date:  That certain date on which all of the
         "Release Conditions" (as said term is defined in the Escrow
         Agreement) are completely satisfied and the Lease is released
         from escrow in accordance with the Escrow Agreement.

         Force Majeure:  Collectively and individually, strike or other
         labor trouble, fire or other casualty, governmental preemption
         of priorities or other controls in connection with a national
         or other public emergency or shortages of, or inability to
         obtain, fuel, supplies or labor resulting therefrom, or acts of
         God, or any other cause, whether similar or dissimilar, beyond
         Landlord's reasonable control.  Force Majeure does not include
         those things that Landlord can cure by the payment of money.

         Force Majeure Date:  The last day of the period of time
         commencing on the Outside Date and terminating at the end of
         the Force Majeure Period.  

         Force Majeure Extension:  The aggregate period of time not to
         exceed sixty (60) days attributable to delays caused by Force
         Majeure which shall only be applicable to Landlord's Holdover
         Contribution in Section 13.12 of this Lease. 

         Force Majeure Period:  The aggregate period of time
         attributable to delays caused by Force Majeure, but in no event
         to exceed in the aggregate six (6) months.

         Ground Lease:  The Indenture of Lease dated as of August 15,
         1980, between the Inhabitants of The Town of Framingham (the
         "Town"), as landlord, and The First National Bank of Boston
         ((the "Bank of Boston"), as tenant, notice of which is recorded
         with the Middlesex South District Registry of Deeds (the
         "Registry") in Book 14036, Page 282 (the "Original Ground
         Lease").  The interest of the Bank of Boston as tenant under
         the Original Ground Lease was assigned to 9/90 Crossing
         Associates Limited Partnership ("9/90") pursuant to that
         certain Lease Assignment dated as of July 29, 1987, and
         recorded with the Registry in Book 18428, Page 050.  The
         interest of "9/90" as tenant under the Original Ground Lease
         was further assigned by "9/90" to Rose Holding, Inc. ("Rose")
         pursuant to that certain Lease Assignment dated as of June 10,
         1994, recorded with the Registry in Book 24620, Page 48. The
         Original Ground Lease was amended by Amendment to Lease dated
         the ______ day of August, 1996 by and between the Town and
         Rose.  All references herein to the Original Ground Lease shall
         mean the Original Ground Lease as so assigned and amended.  The
         interest of Rose as tenant under the Ground Lease and under the
         Original Ground Lease insofar as it relates to Lot B-1 was
         assigned to NDNE 9/90 Crossing Limited Liability Company (the
         "LLC")by Assignment and Assumption of Lease and Collateral
         Agreement with respect to a Portion of the Leasehold Premises
         dated September 30, 1996 from Rose to the LLC (the "First Rose
         Assignment").  The interest of Rose as tenant under the Ground
         Lease and under the Original Ground Lease insofar as it relates
         to the Leasehold Parking Area will be assigned to the Landlord
         hereunder by Assignment and Assumption of Leasehold Interest
         with respect to a Portion of the Leasehold Premises from Rose
         to Landlord (the "Second Rose Assignment"). The Original Ground
         Lease was affected by that certain Consent to Assignment,
         Estoppel Certificate and Agreement of Landlord Respecting
         Ground Lease and Landfill Agreement dated October 7, 1996 and
         recorded in the Registry in Book 26738, Page 303. All
         references in this Lease to the Ground Lease shall mean the
         Original Ground Lease, as amended from time to time, as
         assigned to the LLC by the First Rose Assignment, as assigned
         to Landlord by the Second Rose Assignment and any future
         amendments and any future assignments and, for purposes hereof,
         the premises thereunder shall be deemed to include only the
         Leasehold Parking Area.

         Landfill Lot:  The lot or parcel of land on which the Leasehold
         Parking Area is located as more particularly set forth in
         Exhibit I attached hereto.

         Landlord's Holdover Contribution:  The difference between the
         monthly base rent Tenant will be paying under "Tenant's
         Existing Lease" (as hereinafter defined) on the Anticipated
         Term Commencement Date and (ii) the monthly rent that Tenant
         would be paying under this Lease based on an annual base rent
         of $14.75 per square foot multiplied by the Premises' Square
         Footage; provided, however, in no event shall the Landlord's
         Holdover Contribution exceed $42,500.00 per month.

         Leasehold Parking Area:  The areas designated as the Leasehold
         Parking Area on Exhibit C attached hereto and any alteration or
         replacement (with any such replacement being in close proximity
         to the Building) thereof designated by Landlord in writing to
         Tenant.

         Lot or Lots:  The lot or parcel of land on which the Building
         is or will be located as more particularly set forth in Exhibit
         B attached hereto.

         Lot's Allocable Share:  As defined in Section 13.9.  

         Measurement Method:  The Modified New York BOMA Measurement
         Method 1980, Reaffirmed 1989.

         Outside Date:  The date which is twelve (12) months from the
         date that the Town of Framingham issues a permit for
         construction of the Building, including a foundation permit.

         Park:  The term "Park" shall mean the land described in
         Exhibits A-1 and A-2 of the Park Covenants together with other
         land hereafter added thereto under the Park Covenants and
         together with the buildings, structures and other improvements
         as may, from time to time, be constructed thereon, and all of
         which are referred to in the Park Covenants as "9/90 Crossing". 

         Park Common Expenses:  As defined in Section 13.9.

         Park Common Property:  As defined in Section 13.9.

         Park Covenants:  The Covenants, Restrictions, Development
         Standards and Easements, attached hereto as Exhibit L together
         with any amendments thereto as are permitted thereunder.

         Permitted Uses:   General Office, Research and Development and
         Manufacturing.

         Premises' Square Footage:  Approximately 35,000 rentable square
         feet (to be confirmed by Landlord and Tenant) as determined by
         the Measurement Method, except as follows:  (i) measurements
         will be taken to the inside face of glass on exterior walls,
         even if the glass is not the dominant portion of the exterior
         wall, (ii) measurements to common areas, halls, etc. will be to
         the center line of the partition, (iii) common areas such as
         the first floor lobby, elevator lobbies, cafeteria, locker
         room/shower facilities, common corridors, etc. will be included
         in rentable area, and (iv) any vertical penetrations dedicated
         solely to Tenant's use (i.e. in excess of vertical penetrations
         required to service a standard office building) shall be
         included in usable areas provided, however, any vertical
         penetrations located on the upper two floors of the Building
         and related to the Premises shall not be included in the
         calculation of rentable square footage.  After Tenant delivers
         to Landlord the Tenant's Plans and Specifications, Landlord and
         Tenant shall remeasure the Premises.  If the Premises' Square
         Footage increases or decreases based upon the measurement
         referred to in the preceding sentence, then Landlord and Tenant
         shall enter into an amendment to this Lease for the purpose of
         restating the rentable square feet of the Premises, the Annual
         Fixed Rent, the Premises' Square Footage, the Tenant's
         Proportionate Share and attaching Exhibit A - Plan of Premises
         and Exhibit J - Plan of First Offer Space.

         Property:  The Building (including the Premises), the Lot and
         the Leasehold Parking Area.

         Public Liability Insurance Limit:

         Bodily Injury            Combined single limit of
         and Property Damage      $2,000,000, or greater amount as 
                                  reasonably required by Landlord 
                                  from time to time.

         Reciprocal Easement  Agreement: As defined in Section 5.1.

         Rentable Square Feet in the Building:  Approximately 120,000
         rentable square feet as determined by using the Measurement
         Method, except as follows:  (i) measurements will be taken to
         the inside face of glass on exterior walls, even if the glass
         is not the dominant portion of the exterior walls, (ii)
         measurements to common areas, halls, etc. will be to the center
         line of the partition and (iii) common areas such as the first
         floor lobby, elevator lobbies, cafeteria, locker room/shower
         facilities, common corridors, etc. will be included in rentable
         area.

         Security Deposit:   $750,000.00 (subject to the terms and
         provisions of Section 13.8 hereof).

         Tenant's Access Date:  A date which is the later of (i) March
         1, 1998 or (ii) the date on which Landlord allows Tenant to
         access the Enclosed Building for purposes of commencing
         Tenant's Work.

         Tenant's Existing Lease:  A lease between Cambridge Bioscience
         Corp. and Worcester Business Development Corporation dated
         January 1, 1987, as amended.

         Tenant's Chemicals:  The list of chemicals more particularly
         identified as Tenant's Chemicals in Exhibit O attached hereto,
         as the same may be modified, amended and updated from time to
         time.

         Tenant's Plan Delivery Date:  A date which is the later of (a)
         thirty (30) days after the date of this Lease or (b) the date
         on which Tenant delivers to Landlord the Tenant's Plans and
         Specifications.

         Tenant's Proportionate Share:   Twenty Nine and Seventeen
         Hundredths (29.17%) Percent.

         Tenant's Removable Property:  All articles of personal property
         and all business fixtures, machinery, equipment and furniture
         owned or installed by Tenant and more particularly described as
         Tenant's<PAGE>






         Removable Property in Exhibit H attached hereto shall remain
         the property of Tenant and may be removed by Tenant at any time
         prior to the expiration of this Lease provided that Tenant, at
         its sole cost and expense, shall repair any damage to the
         Building caused by such removal.

         Tenant's Subleasing Profit:  The first $5.00 per square foot of
         any rent, income or profit derived from any sublease of any
         portion of the Premises subleased by Tenant in accordance with
         the provisions of Section 9.13 of this Lease in excess of the
         Annual Fixed Rent ("Tenant's Base Subleasing Profit") plus
         fifty (50%) percent of any rent, income or profit derived from
         any such sublease in excess of Tenant's Base Subleasing Profit.

         Tenant's Work:  As defined in Section 3.4.

         Title Exceptions:  The matters set forth on Exhibit M attached
         hereto and any other rights, easements, encumbrances (excluding
         any mortgage with the exception of any mortgage contemplated in
         Section 12 of this Lease provided that Tenant receives a non-
         disturbance agreement in accordance with Section 12.2 of this
         Lease) and reservations which shall not materially interfere
         with Tenant's rights under this Lease.

         Yield Up Equipment: All of the equipment installed by
         Tenant and more particularly described as Yield Up Equipment in
         Exhibit N attached hereto shall remain the property of Landlord
         at the expiration of the Term or earlier termination of this
         Lease.

         Section 1.2. Exhibits. The following Exhibits are attached to
         and incorporated in this Lease:

              Exhibit A:   Plan of Premises
              Exhibit B:   Lot
              Exhibit C:   Leasehold Parking Area
              Exhibit D:   Building Construction Work
              Exhibit E:   Tenant's Plans and Specifications 
              Exhibit F:   Rules and Regulations
              Exhibit G:   Option to Extend, Right of First Offer
              Exhibit H:   Tenant's Removable Property
              Exhibit I:   Landfill Lot
              Exhibit J:   Plan of First Offer Space
              Exhibit K:   Cleaning Specifications
              Exhibit L:   Park Covenants (Reciprocal Easement
         Agreement)
              Exhibit M:   Title Exceptions
              Exhibit N:   Yield Up Equipment 
              Exhibit O:   Tenant's Chemicals<PAGE>






                                      SECTION 2
                                   Premises and Term

              Section 2.1. Premises. Landlord hereby leases and demises
         the Premises to Tenant and Tenant hereby leases the Premises
         from Landlord subject to the Title Exceptions and subject to
         the terms and provisions of this Lease.  

              Section 2.2. Term. TO HAVE AND TO HOLD for a term
         beginning on the Commencement Date and ending on the close of
         the day immediately preceding the twelfth anniversary of the
         Commencement Date (the "Term") unless sooner terminated as
         hereinafter provided.

              Section 2.3. Appurtenant Rights and Reservations. 

              (a)  Tenant shall have, as appurtenant to the Premises,
         the non-exclusive right to use, and permit its invitees to use
         in common with others, public or common lobbies, hallways,
         stairways, elevators and common walkways necessary for access
         to the Building, the common toilets, corridors and elevator
         lobby of such floor; but such rights shall always be subject to
         the rules and regulations from time to time established by
         Landlord pursuant to this Lease and to the right of Landlord to
         reasonably designate and change from time to time areas and
         facilities so to be used provided such changes do not
         materially affect Tenant's access to or use of the Premises.
         Tenant and its employees shall also have the non-exclusive
         right to use, in common with others entitled thereto, such
         other common areas and facilities in or appurtenant to the
         Building as Landlord may from time to time designate and
         provide.  Subject to the Title Exceptions and subject to the
         terms and provisions of this Lease, Landlord shall provide
         Tenant with the non-exclusive right to use, in common with
         others entitled thereto, that certain number of parking spaces
         on the Leasehold Parking Area equal to four (4) spaces per each
         1,000 square feet of the Premises' Square Footage.  

              (b)  Excepted and excluded from the Premises are
         exterior faces of exterior walls, the common stairways and
         stairwells, elevators and elevator shafts, fan rooms,
         mechanical, freight elevator vestibules and pipes, ducts,
         conduits, wires and appurtenant fixtures serving exclusively or
         in common with other parts of the Building, but included in the
         Premises are all entry doors to the Premises and all special
         installations of Tenant, such as interior stairs, special flues
         and special air conditioning facilities.  Landlord reserves the
         right from time to time, without unreasonable interference with
         Tenant's use:  (a) to install, use, maintain, repair, replace
         and relocate for service to the Premises and other parts of the
         Building, or either, pipes, ducts, conduits, shafts, wires and
         appurtenant fixtures, wherever located in the Premises or
         Building, and (b) to alter or relocate any other common
         facility, provided that substitutions are substantially
         equivalent or better and (c) to maintain, repair, alter and
         replace (with any such replacement being in close proximity to
         the Building) the Leasehold Parking Area and the parking spaces
         located thereon.  Landlord reserves the exclusive use of all
         fan rooms, electric and telephone closets, janitor closets,
         freight elevator vestibules, pipes, ducts, conduits, wires and
         appurtenant fixtures located within the Premises which serve
         exclusively or in common other parts of the Building.

              (c)  Notwithstanding anything to the contrary contained
         in this Lease, the Premises shall be measured using the
         Measurement Method, except as follows:  (i) measurements will
         be taken to the inside face of glass on exterior walls, even if
         the glass is not the dominant portion of the exterior wall,
         (ii) measurements to common areas, halls, etc. will be to the
         center line of the partition, (iii) common areas such as the
         first floor lobby, elevator lobbies, cafeteria, locker room/
         shower facilities, common corridors, etc. will be included in
         rentable area, and (iv) any vertical penetrations dedicated
         solely to Tenant's use (i.e. in excess of vertical penetrations
         required to service a standard office building) shall be
         included in usable areas provided, however, any vertical
         penetrations located on the upper two floors of the Building
         and related to the Premises shall not be included in the
         calculation of rentable square footage.

                                SECTION 3
                       Commencement Date; Improvements

              Section 3.1 Commencement Date.  The Commencement Date
         shall be that date on which (a) the Base Building is
         substantially complete provided that the Town of Framingham has
         issued a Temporary Certificate of Occupancy for the Base
         Building and Landlord has completed each item of Landlord's
         Building Construction Work in accordance with Exhibit D
         (irrespective of whether Tenant has completed Tenant's Work or
         the Town of Framingham has issued a Certificate of Occupancy
         relating to the Premises) and (b) one hundred twenty (120) days
         have elapsed since Tenant's Access Date (unless Tenant
         commences occupancy of any portion of the Premises for the
         Permitted Uses prior to the expiration of said one hundred
         twenty (120) day period, then the date that Tenant commences
         occupancy shall be the applicable date under this clause (b)).
         If Tenant commences occupancy of any portion of the Premises
         prior to the expiration of the one hundred and twenty (120) day
         period referred to in the preceding sentence, then Tenant shall
         commence paying Annual Rent for that portion of the Premises in
         which Tenant takes occupancy; provided, however, upon the
         expiration of said one hundred and twenty (120) day period,
         Tenant shall commence paying Annual Rent for the entire
         Premises.  Each of the parties hereto agrees to, upon demand of
         the other, execute a declaration expressing the Commencement
         Date as soon as the Commencement Date has been determined. 

              Section 3.2   Construction of Building.

              (a)  Landlord, at its expense, shall diligently
         construct the Building substantially in accordance with Exhibit
         D (as the same may be amended in connection with the permit
         approval process for the Premises provided that no such
         amendment affecting the Premises shall be made without the
         approval of Tenant, which approval shall not be unreasonably
         withheld or delayed) (the "Landlord's Building Construction
         Work") and all laws, codes, ordinances and other applicable
         governmental requirements.  Landlord's Building Construction
         Work shall be done in a good and workmanlike manner using first
         quality materials and shall be accomplished in accordance with
         the plans and specifications set forth in Exhibit D.  Tenant
         shall respond promptly to all communications from Landlord and
         shall cooperate with Landlord throughout the construction
         process. Notwithstanding anything contained in Exhibit D to the
         contrary, in no event shall Landlord be obligated to perform
         (or pay for the cost of) the moving or installation of any of
         Tenant's equipment.  Tenant shall pay to Landlord, within ten
         (10) days of billing therefor, any costs of construction
         resulting from changes in Exhibit D requested in writing by
         Tenant, it being understood that such costs shall be equal to
         the aggregate of (a) the "Cost of the Work", as defined in
         American Institute of Architects Document A111 (1987 Edition),
         and (b) Landlord's contractor's overhead and profit in the
         total amount equal to eight percent (8%) of such cost.  

              (b)  Landlord represents, but does not warrant, that on
         the Commencement Date, the Building will be constructed in a
         good and workmanlike manner free from material defects and in
         compliance with all federal, state and local laws, ordinances,
         rules, regulations, orders and permits, including zoning and
         subdivision relating to the Building and the Premises and with
         any restriction, covenant or agreement contained in the Title
         Exceptions.  To the best of Landlord's knowledge, no provision
         contained in any Title Exception interferes with the existing
         or contemplated use of the Premises.

              (c)  Landlord shall procure all necessary permits before
         undertaking Landlord's Building Construction Work; do all of
         such work in a good and workmanlike manner, employing materials
         of first quality and complying with all governmental
         requirements.  Landlord shall cause contractors employed by
         Landlord to carry Workmen's Compensation Insurance in
         accordance with statutory requirements and Comprehensive Public
         Liability Insurance covering such contractors on or about the
         Building.

              Section 3.3  Tenant Improvements; Tenant's Plans and
         Specifications.

              (a)  All work, construction and improvements to be
         performed in or for the Premises in order to prepare same for
         use and occupancy by Tenant set forth in Exhibit E attached
         hereto shall be provided and installed by Tenant at Tenant's
         sole cost and expense.  Prior to commencement of any work by
         Tenant, Tenant shall deliver to Landlord on the Tenant's Plan
         Delivery Date a detailed floor plan layout together with
         construction drawings, working drawings and written
         instructions and specifications (herein called "Tenant's Plans
         and Specifications") in accordance with and containing at least
         the information detailed in Exhibit E and reflecting the
         alterations, work partitions and improvements desired to be
         performed and installed by Tenant in the Premises.  Landlord
         agrees to cooperate with Tenant in the production of those
         portions of Tenant's Plans and Specifications constituting the
         working drawings and written instructions.  Landlord shall not
         be responsible for any cost in connection with preparing
         Tenant's Plans and Specifications. 

              Section 3.4  Tenant's Work.

              (a)  Landlord's approval, which approval shall not be
         unreasonably withheld or delayed, of Tenant's Plans and
         Specifications shall, in no event, be deemed to create any
         obligation on the part of Landlord to do any work or make any
         installations in or about the Premises or to authorize Tenant
         to make any further additions, improvements or alterations to
         the Premises.  

              (b)  Tenant shall perform, at its sole cost and expense,
         all of the work (the "Tenant's Work") shown on Tenant's Plans
         and Specifications substantially in accordance with Tenant's
         Plans and Specifications.  Any changes to Tenant's Plans and
         Specifications (or any variations in Tenant's Work from the
         Tenant's Plans and Specifications) shall be subject to the
         approval of Landlord which approval will not be unreasonably
         withheld or delayed.  Any Tenant Plan provided to Landlord for
         approval under the provisions of this Lease shall be deemed
         approved unless Landlord shall, within ten (10) days of the
         submission of said plan, notify Tenant of the disapproval of
         such plan and the reason(s) for such disapproval.  This
         Subsection (b) and Section 9.4 shall apply before and during
         the Term of this Lease.  All of the Tenant's Work and all
         alterations, additions and installation of furnishings shall be
         coordinated with any work being performed by Landlord in the
         Building and in such manner as to maintain harmonious labor
         relations and not damage the Property or interfere with
         Building construction or operation and shall be performed by
         Tenant's general contractor, which contractor and all
         subcontractors shall be named on a written list submitted to
         Landlord and shall be subject to the written approval of
         Landlord, which approval shall not be unreasonably withheld or
         delayed and any such approval shall be deemed given unless
         Landlord shall within five (5) Business Days of Landlord's
         receipt of Tenant's submission of the name of such contractor
         or subcontractor notify Tenant of Landlord's disapproval of
         such party and the reasons for such disapproval.  Tenant shall
         have the right to use any contractor or subcontractor appearing
         on the list submitted to and approved by Landlord.  Tenant
         acknowledges and agrees that Cranshaw Construction shall have
         the right to bid on all of Tenant's Work, including, without
         limitation, the installation of the roof top HVAC system.
         Tenant hereby assumes all responsibility in connection with
         Tenant's Work.  Tenant shall be responsible for any labor
         difficulties or delays in Tenant's Work and the Commencement
         Date will not be delayed as a result of delays in work.
         Tenant, before its work is started, shall:  secure all
         licenses, approvals and permits necessary therefor and deliver
         copies thereof to Landlord; deliver to Landlord a statement of
         the names of all its contractors and subcontractors and the
         estimated cost of all labor and material to be furnished by
         them; and cause each contractor and subcontractor to carry
         workmen's compensation insurance in statutory amounts covering
         all the contractor's and subcontractor's employees and
         comprehensive public liability insurance and property damage
         insurance with such limits as Landlord may reasonably require
         but in no event less than a $2,000,000.00 combined single limit
         (all such insurance to be written in companies approved by
         Landlord, which approval will not be unreasonably withheld or
         delayed, and insuring Landlord and Tenant as well as the
         contractors), and to deliver to Landlord certificates of all
         such insurance.  Tenant agrees to pay promptly when due the
         entire cost of any work done on the Premises by Tenant, its
         agents, employees, or independent contractors, and not to cause
         or permit any liens for labor or materials performed or
         furnished in connection therewith to attach to the Property and
         immediately to discharge any such liens which may so attach
         and, at the request of Landlord to deliver to Landlord security
         satisfactory to Landlord against liens arising out of the
         furnishing of such labor and material, including, without
         limitation, evidence of bonding over said liens with
         performance, payment and lien bonds in favor of Landlord and
         Tenant.  Upon completion of any work done on the Premises by
         Tenant, its agents, employees, or independent contractors,
         Tenant shall promptly deliver to Landlord original lien
         releases and waivers executed by each contractor,
         subcontractor, supplier, materialmen, architect, engineer or
         other party which furnished labor, materials or other services
         in connection with such work and pursuant to which all liens,
         claims and other rights of such party with respect to labor,
         material or services furnished in connection with such work are
         unconditionally released and waived.  

              (c)  Prior to commencing occupancy, Tenant shall, at its
         sole expense, procure a Certificate of Occupancy for its
         Premises and any other permit or approval required by the Town
         of Framingham or the Commonwealth of Massachusetts for its use
         and occupancy of the Premises and shall deliver copies thereof
         to Landlord.  Entry by Tenant or its agents or contractors for
         the purpose of performing Tenant's Work and/or decorations and/
         or for installation of equipment and furnishings in the
         Premises shall be permitted by Landlord during normal business
         hours on Business Days.  Commencing on Tenant's Access Date,
         Tenant shall have such access as is reasonably necessary to
         allow Tenant to perform Tenant's Work.  Tenant, from and after
         the date of such entry, shall be bound prior to the
         Commencement Date by the provisions contained in this Lease
         (except the obligation to pay Annual Rent, Operating Cost
         Escalations and Real Estate Tax Escalations) notwithstanding
         that such entry and Tenant's Work will occur prior to the
         Commencement Date of this Lease.  In no event shall the
         Commencement Date of this Lease be delayed by reason of
         Tenant's failure to complete the work described in Tenant's
         Plans and Specifications prior to the Commencement Date as it
         is defined in Section 3.1 hereof unless such failure is the
         result of Landlord's failure to fulfill its obligations
         hereunder.  All deliveries of equipment, furnishings, fixtures
         and construction materials and equipment (collectively, "Work
         Materials") to (and all removals of such Work Materials from)
         the Premises in connection with Tenant's Work shall be
         performed in a manner so as to minimize harm to the Building
         and interference with other tenants of the Property.  Tenant
         shall take such protective measures as Landlord may require in
         order to protect the Building or any part thereof from injury
         or damage due to, or in connection with, Tenant's Work.  Tenant
         shall not store any materials or equipment on any sidewalks or
         streets adjacent to the Building caused by Tenant's Work.
         Tenant shall remove all debris, trash and construction rubbish
         from the Premises and the Building.  Tenant shall keep all
         areas of the Building and all sidewalk and street areas
         adjacent to the Building free of trash and debris from Tenant's
         Work and shall, upon completion of its work, clean all areas of
         the Building, sidewalks and streets affected thereby.  Tenant
         shall not damage, deface or injure the Building or any part
         thereof in connection with the Tenant's Work and shall promptly
         reimburse Landlord for the cost of repairing and/or replacing
         any damage, defacement or injury to the Building caused by
         Tenant, its employees, workmen, contractors, subcontractors,
         materialmen and all other parties who are involved in
         performing all or any part of Tenant's Work.  Tenant shall
         comply with all laws, orders, rules, regulations and demands of
         the Town of Framingham in loading and unloading and delivering
         and removing materials relating to Tenant's Work and Tenant's
         Removable Property to and from the Premises.<PAGE>






              Section 3.5  General Provisions Applicable To Tenant Work
         and Landlord Work.  

              All construction work required or permitted by this Lease
         to be performed by either Landlord or Tenant shall be done in a
         good and workmanlike manner and in compliance with all
         applicable provisions of this Lease and all laws and lawful
         ordinances, regulations and orders of governmental authority
         and insurers of the Property, including, without limitation,
         the requirements of the Americans with Disabilities Act of
         1990, as amended.

              Section 3.6  Performance Of Tenant's Work.

              (a)  Landlord shall not unreasonably withhold its
         consent to the general contractor selected by Tenant and
         approved by Landlord ("Tenant's G.C.") performing Tenant's Work
         solely as an accommodation to Tenant.  Tenant hereby
         acknowledges that Landlord is extremely concerned that the
         Tenant's Work be performed in a manner such as to minimize, to
         the maximum extent possible, interference with ongoing work in
         the Building being performed by Landlord, the use and enjoyment
         of other space in the Building by other tenants and the
         continued and uninterrupted operation of all structural,
         mechanical and electrical components of the Building.  Tenant
         further acknowledges that Landlord is vitally interested in
         maintaining the high quality, character and standards of the
         Building as a First Class Office/Research and Development
         Building and that but for the Tenant's assurances given below,
         Landlord would not enter this Lease nor permit Tenant to
         perform Tenant's Work using Tenant's G.C.  Accordingly, in
         order to provide Landlord with the assurances it requires in
         that regard and as a material inducement to the Landlord to
         enter into this Lease, Tenant hereby covenants and agrees with
         Landlord as follows:

         In addition to and without limitation of any other term,
         covenant, provision or condition contained in this Lease
         regarding alterations and improvements to be performed by
         Tenant, the Tenant, for itself and for Tenant's G.C. hereby
         covenants and agrees with Landlord that Tenant, Tenant's G.C.,
         and all of their agents, servants and employees shall comply
         with all directions, orders, instructions, rules, directives
         and regulations now or hereafter implemented or made by
         Landlord's Construction Representative, including, without
         limitation, compliance with any request or order by Landlord's
         Construction Representative to cease and desist from performing
         any part of Tenant's Work.  Landlord's Construction
         Representative shall not act in an arbitrary or capricious
         manner in exercising its rights under this clause.

         Landlord shall provide Tenant with specific guidelines relating
         to Tenant's Work and Tenant shall comply with such guidelines.
         All of Tenant's Work shall be coordinated with any work being
         performed by Landlord in the Building and in such a manner as
         to maintain harmonious labor relations and not damage the
         Property or interfere with the Building construction or
         operation or any other tenant or occupants of the Building.
         Tenant shall comply with the reasonable oral or written
         directions of the Landlord's Construction Representative with
         respect to the covenants of Tenant contained in the foregoing
         clause and if not corrected or completed to the reasonable
         satisfaction of the Landlord's Construction Representative
         within one hour after the giving of such notice then, Landlord
         shall have the right, but not the obligation, in addition to
         all other rights and remedies afforded the Landlord pursuant to
         this Lease, to seek and obtain specific performance of such
         covenants by way of injunctive relief or other equitable
         remedy.

         Tenant shall cause Tenant's G.C. to obtain and maintain (i) a
         payment and performance bond and (ii) a lien bond for the
         benefit of Landlord and Tenant in an amount which is equal to
         the costs of completing Tenant's Work.  Tenant shall provide
         Landlord's Construction Representative with a copy of such bond
         and evidence of its effectiveness before commencing Tenant's
         Work.

              (b)  Tenant's Indemnity with respect to Tenant's Work.
         To the maximum extent this Agreement may be made effective
         according to law, Tenant agrees to indemnify and save Landlord
         harmless from and against any and all loss, cost, penalties,
         liabilities, damages and claims arising from any act, omission
         or negligence of Tenant or Tenant's G.C. (unless Tenant's G.C.
         is Cranshaw Construction) or any contractors or workman
         employed by either of them ("Tenant's Subs") or their
         contractors, licensees, agents, servants or employees arising
         from the performance of Tenant's Work caused to any person or
         to the property of any person, the Building, or the Property.
         In addition, Tenant hereby agrees to indemnify and hold
         Landlord harmless from and against any and all loss, cost, or
         damages incurred by Landlord as a result of any tenant or
         occupant of the building claiming that, as a result of Tenant's
         Work, the conduct of Tenant's G.C.(unless Tenant's G.C. is
         Cranshaw Construction), Tenant's Subs or Tenant's Construction
         Representative, such tenant's use and quiet enjoyment of the
         Building or its respective premises has been damaged or
         destroyed.  This indemnity shall, to the maximum extent this
         agreement may be made effective according to law, also extend
         to all loss, cost, penalties, liability, damage, claims of
         whatever nature asserted against the Landlord arising out of
         the use or occupancy or passage or travel over or upon, the
         Property by Tenant or by any person claiming by, through or
         under Tenant including, without limitation, Tenant's G.C.
         (unless Tenant's G.C. is Cranshaw Construction) and Tenant's
         Subs and their respective agents, employees, contractors and
         customers or arising out of any delivery to or service applied
         to the Premises or on account of or based on anything
         whatsoever done in the Property unless caused by the negligence
         or willful misconduct of Landlord or its servants or agents.
         The indemnity contained in this Section 3.6(b) shall (i)
         include indemnity against all cost, expenses and liabilities
         incurred in or in connection with any such claim or proceeding
         brought thereon and the defense thereof with counsel approved
         by the Landlord and (ii) survive expiration or earlier
         termination of this Lease.  In no event shall Landlord be
         entitled to any indemnity for consequential damages.

              Section 3.7  Delays.

              (a)  On November 1, 1997, Landlord intends to have
         satisfied all the Release Conditions contained in the Escrow
         Agreement, including, without limitation, the condition
         relating to the "Permits", as said term is defined in the
         Escrow Agreement.  If, on December 15, 1997, all of the Release
         Conditions are not completely satisfied or Landlord has not
         commenced construction by placement of forms for the foundation
         of the Building on the Lot, then, at Tenant's election, Tenant
         shall have the right (i) to terminate this Lease by written
         notice to Landlord within three (3) Business Days of December
         15, 1997 or (ii) take thirty (30) days to evaluate its
         situation and, on January 15, 1998, Tenant shall have the right
         to terminate this Lease by written notice to Landlord within
         three (3) Business Days of January 15, 1998.  Any failure of
         Tenant to exercise its rights of termination within three (3)
         Business Days of December 15, 1997 or January 15, 1998, as the
         case may be, shall constitute a waiver of such rights of
         termination on such dates.  Notwithstanding anything to the
         contrary contained in this Lease, once Landlord commences
         construction by placement of forms for the foundation of the
         Building on the Lot and, subject to delays caused by Force
         Majeure, diligently pursues completion of the Base Building,
         then, except as otherwise expressly provided herein, Tenant
         shall have no right to terminate this Lease for delays
         associated with Landlord's completion of the Base Building
         unless Landlord fails to deliver the Base Building on the
         Outside Date or, if delays have been caused by Force Majeure,
         Landlord fails to deliver the Base Building on the Force
         Majeure Date. Landlord shall provide Tenant with written notice
         of any Force Majeure event promptly after the occurrence of
         such event and Landlord's best estimate of the delay caused by
         such event. If, on the Outside Date, Landlord fails to deliver
         the Base Building due to delays caused by reasons other than
         Force Majeure, then Tenant shall have the right to terminate
         this Lease by written notice to Landlord.  Any failure of
         Tenant to exercise its right of termination within three (3)
         Business Days of the Outside Date shall constitute a waiver of
         such right of termination.  If, prior to the Outside Date,
         Landlord anticipates that it will fail to deliver the Base
         Building on the Outside Date due to delays caused by Force
         Majeure, then Landlord shall notify Tenant within three (3)
         Business Days prior to the Outside Date of the reason(s) for
         such failure and Landlord's best estimate of the Force Majeure
         Date, and Landlord shall have an additional period equal to the
         Force Majeure Period in order to deliver the Base Building on
         the Force Majeure Date.  If, on the Force Majeure Date,
         Landlord fails to deliver the Base Building, then Tenant shall
         have the right to terminate this Lease by written notice to
         Landlord.  Any failure of Tenant to exercise its right of
         termination within three (3) Business Days of the Force Majeure
         Date shall constitute a waiver of such right of termination.

              (b)  This Subsection (b) and Section 9.4 shall apply
         before and during the Term.  All of the Tenant's alterations,
         additions and installation of furnishings shall be coordinated
         with any work being performed by Landlord and in such manner as
         to maintain harmonious labor relations and not damage the
         Property or interfere with Building construction or operation
         and, except for Tenant's Work and installation of furnishings,
         shall be performed by Landlord's general contractor or, at
         Landlord's election, by contractors or workmen first approved
         by Landlord.  Except for work by Landlord's general contractor,
         Tenant before its work is started shall:  secure all licenses
         and permits necessary therefor; deliver to Landlord a statement
         of the names of all its contractors and subcontractors and the
         estimated cost of all labor and material to be furnished by
         them; and cause each contractor to carry workmen's compensation
         insurance in statutory amounts covering all the contractor's
         and subcontractor's employees and comprehensive public
         liability insurance and property damage insurance with such
         limits as Landlord may reasonably require but in no event less
         than a combined single limit of Two Million and No/100ths
         ($2,000,000.00) Dollars (all such insurance to be written in
         companies approved by Landlord and insuring Landlord and Tenant
         as well as the contractors), and to deliver to Landlord
         certificates of all such insurance.  Tenant agrees to pay
         promptly when due the entire cost of any work done on the
         Premises by Tenant, its agents, employees, or independent
         contractors, and not to cause or permit any liens for labor or
         materials performed or furnished in connection therewith to
         attach to the Premises or the Property and immediately to
         discharge any such liens which may so attach and, at the
         request of Landlord to deliver to Landlord security
         satisfactory to Landlord against liens arising out of the
         furnishing of such labor and material.  Upon completion of any
         work done on the Premises by Tenant, its agents, employees, or
         independent contractors, Tenant shall promptly deliver to
         Landlord original lien releases and waivers executed by each
         contractor, subcontractor, supplier, materialmen, architect,
         engineer or other party which furnished labor, materials or
         other services in connection with such work and pursuant to
         which all liens, claims and other rights of such party with
         respect to labor, material or services furnished in connection
         with such work are unconditionally released and waived. 

              Section 3.8. General Provisions Applicable to
         Construction.  All construction work required or permitted by
         this Lease, whether performed by Landlord or by Tenant, shall
         be done in a good and workmanlike manner and in compliance with
         all applicable laws, ordinances, regulations, codes and orders
         of any governmental authority. Either party may inspect the
         work of the other at reasonable times and shall give notice of
         observed defects.

              Section 3.9. Construction Representatives. Each party
         authorizes the other to rely in connection with plans and
         construction upon approval and other actions on the party's
         behalf by any Construction Representative of the party named in
         Section 1.1 or any person hereafter designated in substitution
         or addition by notice to the party relying.

              Section 3.10. Changes In Building or Lot.  Landlord shall
         have the right, prior to or during construction of the
         Building, to redesign the Building and/or floors within the
         Building to the extent made necessary by field conditions, by
         requirement of any applicable law, by-law, ordinance or
         municipal authority or otherwise; provided, however, that no
         such redesign shall relieve Landlord of its obligation to
         deliver the Premises, or any portion thereof, in accordance
         with the foregoing provisions of this Section 3 of the Lease
         and further provided that no such redesign shall be made
         without the approval of Tenant, which approval shall not be
         unreasonably withheld or delayed.  In the event any such
         redesign shall be implemented, Landlord shall keep Tenant fully
         advised as to the changes made to the floor plans attached
         hereto as Exhibit A and the parties shall enter promptly into
         an amendment to this Lease reflecting any increase or decrease
         in the area of the Premises, change in the Annual Rent and the
         like resulting from any such redesign.  Landlord also reserves
         the right to change its layout, design and plans for the Lot
         and Leasehold Parking Area and for parking and roadways thereon
         at any time and to add to or reduce the size of the Lot and the
         Leasehold Parking Area; provided that no reduction in the size
         of the Lot may adversely affect the Building or the number of
         parking spaces made available to Tenant under this Lease or
         access ways serving the Building.<PAGE>






                                SECTION 4
                               Annual Rent

              Section 4.1. The Annual Rent. Except as otherwise
         provided in Section 3.1 of this Lease, commencing on the
         Commencement Date, Tenant shall pay the Annual Rent to Landlord
         at the Address of Landlord or at such other place or to such
         other person or entity as Landlord may by notice to Tenant from
         time to time direct, at the Annual Fixed Rent set forth in
         Section 1, in equal installments equal to 1/12th of the Annual
         Fixed Rent in advance on the first day of each calendar month
         included in the Term, and for any portion of a calendar month
         at the beginning or end of the Term, at that pro-rated rate
         payable in advance for such portion, and the Additional Rent in
         accordance with the terms and provisions of this Lease. Tenant
         shall pay a late charge equal to five (5%) percent of the
         amount of any Annual Rent payment or other charge which is not
         paid when due.

                                SECTION 5
                         Operating Cost Escalation

              Section 5.1. Operating Cost Escalation. Tenant shall pay
         to Landlord, as Additional Rent, Operating Cost Escalation (as
         defined below) on or before the 10th day following receipt by
         Tenant of Landlord's Operating Cost Statement (as defined
         below). 

              As used herein, the term "Landlord's Operating Costs"
         shall mean all of the following:   premiums for insurance;
         compensation and all fringe benefits, worker's compensation,
         insurance premiums and payroll taxes paid by Landlord to, for
         or with respect to all persons engaged in the managing,
         operating, maintaining or cleaning of the Property; water and
         sewer use charges for the Property; all common area utility
         charges not billed directly to tenants by Landlord or the
         utility; payments to contractors and management companies under
         service or management contracts (or other costs incurred
         directly by Landlord or its agents) for operating, managing,
         cleaning, maintaining and repairing the Property, including,
         without limitation, management fees, Building cleaning, window
         cleaning, pest extermination, trash removal, landscaping, snow
         removal and repair and maintenance to elevators, the common
         area HVAC, electric and plumbing systems and the parking area
         (which payments may be to affiliates of Landlord, provided the
         same are at reasonable rates), and all other reasonable and
         necessary expenses paid in connection with the cleaning,
         operating, managing, maintaining and repairing of the Property,
         or any of them, and properly chargeable against income; it
         being agreed that if Landlord shall install a new or
         replacement capital item for the purpose of complying with
         applicable laws or regulations or intended to reduce Landlord's
         Operating Costs, the annual amortization (reasonably determined
         by Landlord over the useful life of the asset) of the cost
         thereof, with interest thereon at an annual rate equal to two
         (2%) percent above the base rate (prime rate) of BankBoston (or
         any other Bank having offices in Boston, Massachusetts chosen
         by Landlord) from time to time, shall be included in Landlord's
         Operating Costs; all costs and expenses allocated to the
         Property under that certain "Declaration of Covenants,
         Restrictions, Development Standards and Easements" dated
         December 30, 1996 and recorded in the Middlesex South District
         Registry of Deeds in Book 26738, Page 245, as the same may be
         amended, restated, modified, changed, supplemented or
         substituted from time to time (the "Reciprocal Easement
         Agreement"), including, without limitation, all costs and
         expenses of operating, maintaining, lighting, plowing and
         repairing the Leasehold Parking Area, shall be included in
         Landlord's Operating Costs. 

              Within sixty (60) days of the end of each calendar year
         during the Term and after Lease termination, Landlord shall
         render a statement ("Landlord's Operating Cost Statement") in
         reasonable detail and according to usual accounting practices,
         certified by Landlord, and showing for the preceding calendar
         year or fraction thereof, as the case may be, Landlord's
         Operating Costs (as defined below), excluding the interest and
         amortization on mortgages for the Building and Lot, the cost of
         special services rendered to tenants (including Tenant) for
         which a special charge is made, real estate taxes on the
         Building and Lot (including installments and interest on
         assessments for public betterments or public improvements and
         expenses of any proceedings for abatement of taxes and
         assessments with respect to any fiscal year or fraction of a
         fiscal year) and any costs relating to remediation of any
         hazardous materials on the Lot and the Leasehold Parking Area
         in connection with closure of the landfill on the Landfill Lot. 

              If, during the Term of this Lease, Landlord shall incur
         capital expenses in connection with repairs to the roof,
         foundation or structure of the Building directly related to any
         equipment installed and used by Tenant in the Building, there
         shall be included in the amount of the annual amortization
         (determined by Landlord) of the cost thereof, with interest
         thereon, at an annual rate equal to two (2%) percent above the
         base rate (prime rate) of BankBoston (or any other bank having
         offices in Boston, Massachusetts chosen by Landlord) from time
         to time in effect at the time of making such capital repairs
         (less insurance proceeds or other proceeds, if any, collected
         by Landlord by reason of damage to, or destruction of, any
         capital items so repaired. 

              If Annual Base Operating Costs exceed Landlord's
         Operating Costs for any Lease Year during the Term as evidenced
         by Landlord's Operating Cost Statement, then Landlord shall
         credit Tenant the amount equal to the product of:  (i) Tenant's
         Proportionate Share times (ii) the excess of the Annual Base
         Operating Costs over the Landlord's Operating Costs for the
         applicable Lease Year as evidenced by Landlord's Operating Cost
         Statement for the applicable Lease Year, against the next
         payment(s) of Annual Fixed Rent (or refund such overpayment if
         the Term of this Lease has ended and Tenant has no further
         obligation to Landlord).

              "Operating Cost Escalation" shall be equal to Tenant's
         Proportionate Share of the excess, if any, of:

              (a) Landlord's Operating Costs for each calendar year as
         indicated by Landlord's Operating Cost Statement; over

              (b) The Annual Base Operating Costs.

              Operating Cost Escalations shall be apportioned for any
         calendar year in which the Lease Term commences or ends.
         Notwithstanding any other provision of this Section 5.1, if the
         Term expires or is terminated as of a date other than the last
         day of a calendar year, then for such fraction of a calendar
         year at the end of the Term, Tenant's last payment to Landlord
         under this Section 5.1 shall be made on the basis of Landlord's
         best estimate of the items otherwise includable in Landlord's
         Operating Cost Statement and shall be made on or before the
         later of (a) 10 days after Landlord delivers such estimate to
         Tenant, or (b) the last day of the Term, with an appropriate
         payment or refund to be made upon submission of Landlord's
         Operating Cost Statement.  Tenant shall have the right, at
         Tenant's expense to audit Landlord's Operating Cost Statement
         within ninety (90) days after Landlord provides Tenant with
         said statement provided, however, that in no event shall Tenant
         have the right to conduct more than one such audit in any
         calendar year.

              Section 5.2. Estimated Operating Cost Escalation
         Payments. If, with respect to any calendar year or fraction
         thereof during the Term, Landlord reasonably estimates that
         Tenant shall be obligated to pay Operating Cost Escalation,
         then Tenant shall pay, as Additional Rent, on the first day of
         each month of such calendar year and each ensuing calendar year
         thereafter, estimated monthly escalation payments equal to 1/
         12th of the estimated Operating Cost Escalation for the
         respective calendar year, with an appropriate additional
         payment or refund to be made within 30 days after Landlord's
         Operating Cost Statement is delivered to Tenant. Landlord may
         adjust such estimated monthly escalation payment from time to
         time and at any time during a calendar year, and Tenant shall
         pay, as Additional Rent, on the first day of each month
         following receipt of Landlord's notice thereof (which notice
         shall be accompanied by appropriate documentation supporting
         such adjustment), the adjusted estimated monthly escalation
         payment.

                                SECTION 6
                        Real Estate Tax Escalation.

              Section 6.1. Real Estate Tax Escalation. Tenant shall pay
         to Landlord, as Additional Rent, Real Estate Tax Escalation (as
         defined below) on or before the thirtieth (30th) day following
         billing therefor by Landlord.

              As used herein, the term "Real Estate Taxes" shall mean
         all taxes, assessments (special, betterment or otherwise),
         levies, fees, water and sewer rents and charges, and all other
         government levies and charges, general and special, ordinary
         and extraordinary, foreseen and unforeseen, which are allocable
         to the Term hereof and imposed or levied upon or assessed
         against the Property. Nothing herein shall, however, require
         Tenant to pay any income taxes, excess profits taxes, excise
         taxes, franchise taxes, estate, succession, inheritance or
         transfer taxes, provided, however, that if at any time during
         the Term the present system of ad valorem taxation of real
         property shall be changed so that in lieu of the whole or any
         part of the ad valorem tax on real property, or in lieu of
         increases therein, there shall be assessed on Landlord a
         capital levy or other tax on the gross rents received with
         respect to the Property or a federal, state, county, municipal,
         or other local income, franchise, excise or similar tax,
         assessment, levy or charge (distinct from any now in effect)
         measured by or based, in whole or in part, upon gross rents,
         then any and all of such taxes, assessments, levies or charges,
         to the extent so measured or based ("Substitute Taxes"), shall
         be included as real estate taxes hereunder, provided, however,
         that Substitute Taxes shall be limited to the amount thereof as
         computed at the rates that would be payable if the Building and
         the Lot were the only property of Landlord.  The term "real
         estate taxes" shall also mean all real estate taxes and
         assessments (or any substitute therefor) which are allocated to
         the Property under the Reciprocal Easement Agreement.

              "Real Estate Tax Escalation" shall be equal to Tenant's
         Proportionate Share of the excess, if any, of:

              (a) Real Estate Taxes for the applicable tax fiscal year
         occurring during the Term; over

              (b) the Annual Base Real Estate Taxes.

              Notwithstanding any other provision of this Section 6.1,
         if the Term expires or is terminated as of a date other than
         the last date of a tax fiscal year, then for such fraction of a
         tax fiscal year at the end of the Term, Tenant's last payment
         to Landlord under this Section 6.1 shall be made to reflect
         that only a portion of such tax fiscal year falls within the
         Term of this Lease and shall be made within 10 days after
         Landlord bills Tenant therefor.

              Section 6.2. Estimated Real Estate Escalation
         Payments. If, with respect to any tax fiscal year or fraction
         thereof during the Term, Landlord reasonably estimates that
         Tenant shall be obligated to pay Real Estate Tax Escalation,
         Tenant shall pay, as Additional Rent, on the first day of each
         month of such tax fiscal year and each ensuing tax fiscal year
         thereafter, estimated monthly escalation payments equal to 1/
         12th of the estimated Real Estate Tax Escalation for the
         respective tax fiscal year, with an appropriate additional
         payment or refund to be made within 30 days after Landlord's
         delivery of the tax bills for such period to Tenant. Landlord
         may adjust such estimated monthly escalation payment from time
         to time and at any time during a tax fiscal year, and Tenant
         shall pay, as Additional Rent, on the first day of each month
         following receipt of Landlord's notice thereof, the adjusted
         estimated monthly escalation payment.

              Section 6.3.  Assessment of Property.  If Annual Base
         Real Estate Taxes exceed the Real Estate Taxes assessed against
         the Property for any fiscal year (the "Actual Annual Taxes"),
         then Landlord shall credit Tenant the amount equal to the
         product of: (i) Tenant's Proportionate Share times (ii) the
         excess of the Annual Base Real Estate Taxes over the Actual
         Annual Taxes for the applicable fiscal year, against the next
         payment(s) of Annual Fixed Rent (or refund such overpayment if
         the Term of this Lease has ended and Tenant has no further
         obligation to Landlord).

                                SECTION 7
                               Insurance 

              Section 7.1. Tenant's Insurance. Tenant shall, as
         additional rent, maintain throughout the Term the following
         insurance:

                   (a) Commercial general liability insurance for any
         injury to person or property occurring on the Premises, naming
         as insureds Tenant, Landlord and such persons, including,
         without limitation, Landlord's managing agent, as Landlord
         shall designate from time to time, in amounts which shall, at
         the beginning of the Term, be at least equal to the limits set
         forth in Section 1, and, from time to time during the Term,
         shall be for such higher limits as are reasonably required by
         Landlord; and

                   (b) Worker's compensation insurance with statutory
         limits covering all of Tenant's employees working at the
         Premises; and

                   (c)  Environmental liability insurance for any
         release or threat of release of "Hazardous Materials" (as said
         term is defined in Section 13.11 hereof) occurring on the
         Property as a result of Tenant's use and operation of the
         Premises, naming as insureds, Tenant, Landlord and such
         persons, including, without limitation, Landlord's managing
         agent and Landlord's mortgagee, as Landlord shall designate
         from time to time, in such amounts as are reasonably required
         by Landlord, but in no event less than (1) $1,000,000 per claim
         for Pollution Legal Liability Select Coverage and (ii)
         $2,000,000 in the aggregate for bodily injury, property damage
         and clean up costs.  Tenant acknowledges and agrees that if
         Landlord is required to obtain any special environmental
         insurance as a result of Tenant's use and occupancy of the
         Property, then Tenant shall pay for any insurance premiums
         related thereto which insurance premiums shall be included in
         Landlord's Operating Costs.

              Section 7.2. Requirements Applicable to Insurance
         Policies. All policies for insurance required under the
         provisions of Section 7.1 shall be obtained from responsible
         companies qualified to do business in the Commonwealth of
         Massachusetts and in good standing therein, which companies and
         the amount of insurance allocated thereto shall be subject to
         Landlord's approval, which approval shall not be unreasonably
         withheld or delayed. Tenant agrees to furnish Landlord with
         insurance company certificates of all such insurance and copies
         of the policies therefor prior to the beginning of the Term
         hereof and of each renewal policy at least thirty (30) days
         prior to the expiration of the policy it renews. Each such
         policy shall be noncancellable with respect to the interest of
         Landlord and such mortgagees without at least thirty (30) days'
         prior written notice thereto.

              Section 7.3. Waiver of Subrogation. All insurance which
         is carried by either party with respect to the Premises or to
         furniture, furnishings, fixtures or equipment therein or
         alterations or improvements thereto, whether or not required,
         shall include provisions which either designate the other party
         as one of the insureds or deny to the insurer acquisition by
         subrogation of rights of recovery against the other party to
         the extent such rights have been waived by the insured party
         prior to occurrence of loss or injury, insofar as, and to the
         extent that such provisions may be effective without making it
         impossible to obtain insurance coverage from responsible
         companies qualified to do business in the Commonwealth of
         Massachusetts (even though extra premium may result therefrom)
         and without voiding the insurance coverage in force between the
         insurer and the insured party. On reasonable request, each
         party shall be entitled to have duplicates or certificates of
         policies containing such provisions. Each party hereby waives
         all rights of recovery against the other for loss or injury
         against which the waiving party is protected by insurance
         containing said provisions, reserving, however, any rights with
         respect to any excess of loss or injury over the amount
         recovered by such insurance.

                                SECTION 8
                           Landlord's Covenants

              Section 8.1. Quiet Enjoyment. Tenant, on paying the rent
         and performing its obligations hereunder, shall peacefully and
         quietly have, hold and enjoy the Premises throughout the Term
         without any manner of hindrance or molestation from Landlord or
         anyone claiming under Landlord, subject, however, to all the
         terms and provisions hereof.

              Section 8.2. Maintenance and Repair. Subject to the
         provisions of Section 10, Landlord shall maintain the roof,
         structural supports, foundation and exterior of the Building
         and all standard plumbing, electrical, mechanical, heating,
         ventilating and air conditioning systems installed by Landlord
         (but excluding all special systems installed by Tenant or by
         Landlord at Tenant's request) in good condition and shall
         maintain and clean the common areas of the Building and the
         Lot, the cost of which shall be included in Landlord's
         Operating Costs.

              Section 8.3. Electricity, Water and Gas.   Electricity,
         water and gas to the Premises shall be separately metered or
         check metered and all utility charges for lights and plugs,
         water and gas serving the Premises shall be billed directly to,
         and paid by, Tenant.  If in Landlord's reasonable judgment,
         Tenant's use of electricity, water and gas in excess of normal
         office usage shall result in an additional burden on the
         Building's utility systems or additional cost on account
         thereof, as the case may be, Tenant shall upon demand reimburse
         Landlord for all additional costs related thereto.  Landlord,
         at Tenant's expense, shall replace and install all ballasts,
         lamps and bulbs (including, but not limited to, incandescent
         and fluorescent) used in the Premises. All such replacements
         shall be of a type, color and size as shall be designated by
         Landlord.  Landlord shall not in any way be liable or
         responsible to Tenant for any loss, damage or expense which
         Tenant may sustain or incur if the quantity, character, or
         supply of electricity is changed or is no longer available or
         suitable for Tenant's requirements.

              Section 8.4. HVAC.  All charges for any air conditioning,
         heating and ventilation systems servicing the Premises shall be
         billed directly to, and paid by Tenant, except for any portion
         of the Premises occupied by Tenant where Landlord provides the
         air conditioning, heating and ventilation services.  Tenant
         shall pay for any charges, costs and expenses associated with
         the use, repair, maintenance and replacement of any air
         conditioning, heating and ventilation system servicing the
         Premises.  Landlord shall, on Business Days and generally
         during Business Hours furnish heating and cooling as normal
         seasonal changes may require to provide reasonably comfortable
         space temperature and ventilation for common areas of the
         Building, and Tenant shall pay Tenant's Proportionate Share of
         any costs and expenses associated with such services.  In the
         event Tenant introduces into the Premises personnel or
         equipment which overloads the capacity of the Building system
         or in any other way interferes with the system's ability to
         perform adequately its proper functions, or which affects the
         temperature otherwise maintained by the air-conditioning
         system, supplementary systems may, if and as needed, at
         Landlord's option, be provided by Landlord, at Tenant's
         expense.

              Section 8.5. Cleaning.  With respect to the common areas
         of the Building, Landlord shall provide nightly cleaning
         services as more particularly described in Exhibit K attached
         hereto for said portions of the Building (Mondays through
         Fridays only) commensurate with industry standards for office
         buildings comparable to the Building located in Framingham,
         Massachusetts.

              Section 8.6. Interruptions.  

              (a)  Landlord shall not be liable to Tenant for any
         compensation or reduction of rent by reason of inconvenience or
         annoyance or for loss of business arising from power losses or
         shortages or from the necessity of Landlord's entering the
         Premises for any of the purposes authorized by this Lease or
         for repairing the Premises or any portion of the Building or
         Lot or Leasehold Parking Area. In case Landlord is prevented or
         delayed from making any repairs, alterations or improvements,
         or furnishing any service or performing any other obligation to
         be performed on Landlord's part, by reason of any cause,
         Landlord shall not be liable to Tenant therefor, nor shall
         Tenant be entitled to any abatement or reduction of rent by
         reason thereof, nor shall the same give rise to any claim by
         Tenant that such failure constitutes actual or constructive,
         total or partial, eviction from the Premises.  Landlord
         reserves the right to stop any service or utility system when
         necessary by reason of accident or emergency or until necessary
         repairs have been completed. Except in case of emergency
         repairs, Landlord will give Tenant reasonable advance notice of
         any contemplated stoppage and will use reasonable efforts to
         avoid unnecessary inconvenience to Tenant by reason thereof.
         Landlord also reserves the right to institute such policies,
         programs and measures as may be necessary, required or
         expedient for the conservation or preservation of energy or
         energy services or as may be necessary or required to comply
         with applicable codes, rules, regulations or standards. In so
         doing, Landlord shall make reasonable efforts to avoid
         unnecessary inconvenience to Tenant by reason thereof.

              (b)  Notwithstanding anything contained in this Lease to
         the contrary, if (i) an interruption or curtailment, suspension
         or stoppage of an Essential Service (as said term is
         hereinafter defined) shall occur (any such interruption of an
         Essential Service being hereinafter referred to as a "Service
         Interruption"), (ii) such Service Interruption occurs or
         continues as a result of an involuntary interruption, stoppage
         or suspension of Essential Services by Landlord or as the
         result of any circumstance which is subject to the control of
         Landlord, (iii) such Service Interruption continues for more
         than forty five (45) consecutive calendar days after Landlord
         shall have received notice thereof from Tenant, (which notice
         shall specifically refer to the provisions of this paragraph)
         and (iv) as a result of such Service Interruption, the conduct
         of Tenant's normal operations in the Premises are materially
         and adversely affected, then there shall be an abatement of one
         day's Annual Fixed Rent for each day during which such Service
         Interruption continues provided, further, that if any part of
         the Premises is reasonably useable for Tenant's operations or
         if Tenant conducts all or any part of its operations in the
         Premises notwithstanding such Service Interruption, then the
         amount of each daily abatement of Annual Fixed Rent shall only
         be proportionate to the nature and extent of the interruption
         of Tenant's normal operations.  The rights granted under this
         paragraph shall be personal to the original Tenant and shall
         terminate upon any assignment of the Lease or any subletting of
         all or any portion of the Premises outstanding at any one time.
         For purposes hereof, the term "Essential Services" shall mean
         the following services, to the extent that Landlord has agreed
         to provide any of them to Tenant pursuant to this Lease:
         elevator service, heating, air-conditioning, water and
         electricity.  Any abatement of Annual Fixed Rent under this
         paragraph shall apply only with respect to Annual Fixed Rent
         allocable to the period after each of the conditions set forth
         in subsections (i) through (iv) hereof shall have been
         satisfied.

              Section 8.7.  Representations.

              (a)  To the best of Landlord's knowledge, Landlord
         represents, but does not warrant, that:  (i) it has good clear
         record and marketable title to the Lot, free and clear of all
         encumbrances or obligations affecting the Lot other than the
         Title Exceptions and any other rights, easements, encumbrances
         and reservations which shall not materially interfere with
         Tenant's rights under the Lease.  To the best of Landlord's
         knowledge, there is no pending or threatened condemnation or
         eminent domain proceeding with respect to the Lot.  To the best
         of Landlord's knowledge, the Lot is legally subdivided and
         consists of a separate tax lot so that it will be assessed
         separate and apart from any other property.  To the best of
         Landlord's knowledge, there are no suits, notices or
         proceedings pending, or to the best of Landlord's knowledge,
         threatened by any persons or government agencies before any
         court, governmental agency or instrumentality administrative or
         otherwise which would have an affect on Landlord's title to the
         Lot.

              (b)  Landlord is the assignee of Tenant's interest under
         the Ground Lease, and, to the best of Landlord's knowledge,
         Landlord's interest is free and clear of any liens or
         encumbrances, except for the Title Exceptions and any other
         rights, easements, encumbrances and reservations which shall
         not materially interfere with Tenant's rights under the Lease.
         To the best of Landlord's knowledge, true, correct and complete
         copies of the Ground Lease and all amendments, modifications
         and supplemental agreements thereto have previously been
         delivered to Landlord.  To the best of Landlord's knowledge,
         the Ground Lease is in full force and affect and is binding and
         enforceable against each of the parties thereto in accordance
         with its terms and has not  been modified or amended since the
         date of delivery to Tenant.  To the best of Landlord's
         knowledge, there has not occurred any event which would
         constitute a breach of or default in the performance of any
         material covenant, agreement or condition contained in the
         Ground Lease, nor has there occurred any events which with the
         passage of time, giving of notice or both would constitute such
         a breach or material default.  Landlord shall perform and
         observe all of the terms, covenants and conditions required to
         be performed by Landlord as tenant under the Ground Lease.

              Section 8.8. Estoppel Certificates.  Landlord shall at
         any time and from time to time upon not less than ten (10)
         days' prior notice by Tenant to Landlord, execute, acknowledge
         and deliver to Tenant a statement in writing certifying that
         this Lease is unmodified and in full force and effect (or if
         there have been modifications, that the same is in full force
         and effect as modified and stating the modifications), and the
         dates to which the rent and other charges have been paid in
         advance, if any, and stating whether or not to the best of
         Landlord's knowledge, Tenant is in default in performance of
         any covenant, agreement, term, provision or condition contained
         in this Lease and, if so specifying each such default of which
         the Landlord may have knowledge.

                                SECTION 9
                            Tenant's Covenants

              Section 9.1. Use. Tenant shall use the Premises only for
         the Permitted Uses and shall from time to time procure all
         licenses and permits necessary therefor at Tenant's sole
         expense.

              Section 9.2. Repair and Maintenance. Except as otherwise
         provided in Sections 8 and 10, Tenant shall keep the Premises,
         including all plumbing, electrical, heating, air conditioning
         and other systems therein, in good order, condition and repair
         and in at least as good order, condition and repair as they are
         in on the Commencement Date or may be put in during the Term,
         reasonable use and wear only excepted. Tenant shall make all
         repairs and replacements and do all other work necessary for
         the foregoing purposes whether the same may be ordinary or
         extraordinary, foreseen or unforeseen. Tenant shall keep in a
         safe, secure and sanitary condition all trash and rubbish
         temporarily stored at the Premises.

              Section 9.3. Compliance with Law and Insurance
         Requirements. Tenant shall comply with all laws, rules,
         regulations, codes and ordinances including, without
         limitation, OSHA, NIH and FDA regulations, in its use and
         occupancy of the Property.  Tenant shall make all repairs,
         alterations, additions or replacements to the Premises required
         by any law or ordinance or any order or regulation of any
         public authority arising from Tenant's use of the Premises and
         shall keep the Premises equipped with all safety appliances so
         required. Tenant shall not release, dump, flush, or in any way
         introduce any "Hazardous Materials" (as said term is defined in
         Section 13.11 hereof) into the septic, sewage or other waste
         disposal system serving the Premises, or generate, store,
         transfer or dispose of Hazardous Materials in or on the
         Premises or dispose of Hazardous Materials from the Premises to
         any other location except in compliance with "Environmental
         Laws" (as said term is defined in Section 13.11 hereof). Tenant
         shall notify Landlord of any incident which would require the
         filing of a notice under the Environmental Laws.  

              Landlord may, if it so elects, make any of the repairs,
         alterations, additions or replacements referred to in this
         Section which affect the Building structure or the Building
         systems, and Tenant shall reimburse Landlord for the cost
         thereof on demand.

              Tenant will provide Landlord, from time to time upon
         Landlord's request, with all records and information regarding
         any Hazardous Materials maintained on the Premises by Tenant.

              Landlord shall have the right to make such inspections as
         Landlord shall reasonably elect from time to time to determine
         if Tenant is complying with this Section and if any of such
         inspections reveals contamination by Hazardous Materials of the
         Property as a result of Tenant's operations or actions or the
         actions of Tenant's agents, contractors or employees, Tenant
         shall reimburse Landlord for the cost of performing (or
         contracting for) such inspections.

              Tenant shall comply promptly with the recommendations of
         any insurer, foreseen or unforeseen, ordinary as well as
         extraordinary, which may be applicable to the Property, by
         reason of Tenant's use thereof. In no event shall any activity
         be conducted by Tenant on the Property which may give rise to
         any cancellation of any insurance policy or make any insurance
         unobtainable.

              Section 9.4. Tenant's Alterations.  Landlord and Tenant
         agree that this Section 9.4 shall apply to any future
         installations, alterations, additions or improvements in or to
         the Premises occurring after the construction of Tenant's Work
         in accordance with Section 3.4 hereof.  Tenant shall not make
         any installations, alterations, additions or improvements in or
         to the Premises, including, without limitation, any apertures
         in the walls, partitions, ceilings or floors, without on each
         occasion obtaining the prior written consent of Landlord, which
         consent shall not be unreasonably withheld or delayed. Any such
         work so consented to by Landlord shall be performed only in
         accordance with plans and specifications therefor approved by
         Landlord which approval shall not be unreasonably withheld or
         delayed. Tenant shall procure at Tenant's sole expense all
         necessary permits and licenses before undertaking any work on
         the Premises and shall perform all such work in a good and
         workmanlike manner employing materials of good quality and so
         as to conform with all applicable zoning, building, fire,
         health and other codes, regulations, ordinances and laws and
         with all applicable insurance requirements.  Tenant agrees to
         pay promptly when due the entire cost of any work done on the
         Premises by Tenant, its agents, employees or independent
         contractors, and not to cause or permit any liens for labor or
         materials performed or furnished in connection therewith to
         attach to the Property and to discharge any such liens which
         may so attach within five (5) calendar days and, at the request
         of Landlord, to deliver to Landlord security satisfactory to
         Landlord against liens arising out of the furnishing of such
         labor and material, including, without limitation, evidence of
         bonding over said liens with performance, payment and lien
         bonds in favor of Landlord and Tenant; Landlord and Tenant
         agree that payment and performance bonds shall only be
         necessary for any work for which the total contract sum exceeds
         $100,000.00.  Tenant shall employ for such work only
         contractors approved by Landlord, which approval shall not be
         unreasonably withheld or delayed, and shall require all
         contractors employed by Tenant to carry worker's compensation
         insurance in accordance with statutory requirements and
         comprehensive general liability insurance covering such
         contractors, and naming Landlord and Tenant as additional
         insureds, on or about the Premises in amounts at least equal to
         the limits set forth in Section 1 and to submit certificates
         evidencing such coverage to Landlord prior to the commencement
         of such work. Tenant shall save Landlord harmless and
         indemnified from all injury, loss, claims or damage to any
         person or property occasioned by or growing out of such work.
         Landlord may inspect the work of Tenant at reasonable times and
         give notice of observed defects.

              Section 9.5. Indemnity. Tenant shall defend, with counsel
         reasonably approved by Landlord, all actions against Landlord,
         any member, partner, trustee, stockholder, officer, director,
         employee or beneficiary of Landlord, holders of mortgages
         secured by the Building and any other party having an interest
         in the Premises ("Indemnified Parties") with respect to, and
         shall pay, protect, indemnify and save harmless, to the extent
         permitted by law, all Indemnified Parties from and against, any
         and all liabilities, losses, damages, costs, expenses
         (including reasonable attorneys' fees and expenses), causes of
         action, suits, claims, demands or judgments of any nature
         arising from (a) injury to or death of any person, or damage to
         or loss of property, occurring in the Premises unless caused by
         the negligence or willful misconduct of Landlord or its
         servants or agents, (b) violation of this Lease by Tenant, or
         (c) any wrongful act or other misconduct of Tenant or its
         agents, general contractor (unless Tenant's G.C. is Cranshaw
         Construction), contractors, subcontractors, licensees,
         sublessees or invitees.  The indemnity contained in this
         Section 9.5 shall survive any expiration or earlier termination
         of this Lease. In no event shall Landlord be entitled to any
         indemnity for consequential damages.

              Section 9.6. Landlord's Right to Enter. Tenant shall
         permit Landlord and its agents to enter into the Premises at
         reasonable times and upon reasonable notice (except that in
         emergencies no notice shall be required) to examine the
         Premises, make such repairs and replacements as Landlord may
         elect, without however, any obligation to do so, and show the
         Premises to prospective purchasers and lenders, and, during the
         last nine (9) months of the Term, to show the Premises to
         prospective tenants and to keep affixed in suitable places
         notices of availability of the Premises.

              Section 9.7. Personal Property at Tenant's Risk. All
         furnishings, fixtures, equipment, effects and property of every
         kind of Tenant and of all persons claiming by, through or under
         Tenant which may be on the Premises, shall be at the sole risk
         and hazard of Tenant and if the whole or any part thereof shall
         be destroyed or damaged by fire, water or otherwise, or by the
         leakage or bursting of water pipes, steam pipes, or other
         pipes, by theft or from any other cause, no part of said loss
         or damage shall be charged to or to be borne by Landlord,
         except that Landlord shall in no event be indemnified or held
         harmless or exonerated from any liability to Tenant for any
         injury, loss, damage or liability not covered by Tenant's
         insurance to the extent prohibited by law. Tenant shall insure
         Tenant's personal property.

              Section 9.8. Yield Up. At the expiration of the Term or
         earlier termination of this Lease, Tenant shall surrender all
         keys to the Premises, remove all of Tenant's Removable Property
         and repair all damage caused by such removal including, without
         limitation, any repairs to the roof of the Building required as
         a result of such removal and yield up (i) the Premises (broom-
         clean and in the same good order and repair in which Tenant is
         obliged to keep and maintain the Premises under this Lease) and
         (ii) the Yield Up Equipment.  Any of Tenant's Removable
         Property, not so removed shall be deemed abandoned and may be
         removed and disposed of by Landlord in such manner as Landlord
         shall determine, and Tenant shall pay Landlord the entire cost
         and expense incurred by it in effecting such removal and
         disposition and in making any incidental repairs and
         replacements to the Premises and for use and occupancy during
         the period after the expiration of the Term and prior to
         Tenant's performance of its obligations under this Section 9.8.

              Section 9.9. Estoppel Certificate. Upon not less than
         five (5) business days' prior notice by Landlord, Tenant shall
         execute, acknowledge and deliver to Landlord a statement in
         writing certifying that this Lease is unmodified and in full
         force and effect and that, except as stated therein, Tenant has
         no knowledge of any defenses, offsets or counterclaims against
         its obligations to pay the Annual Rent and any other charges
         and to perform its other covenants under this Lease (or, if
         there have been any modifications that the same is in full
         force and effect as modified and stating the modifications and,
         if there are any defenses, offsets or counterclaims, setting
         them forth in reasonable detail), the dates to which the Annual
         Rent and other charges have been paid and a statement that
         Landlord is not in default hereunder (or if in default, the
         nature of such default, in reasonable detail). Any such
         statement delivered pursuant to this Section 9.9 may be relied
         upon by any prospective purchaser or mortgagee of the Building.

              Section 9.10. Landlord's Expenses Re Consents. 
         Intentionally Omitted.

              Section 9.11. Rules and Regulations. Tenant shall comply
         with the Rules and Regulations attached hereto as Exhibit F
         attached hereto and such additional reasonable rules and
         regulations as may be adopted from time to time by Landlord to
         provide for the beneficial operation of the Property.

              Section 9.12. Holding Over. Tenant shall vacate the
         Premises immediately upon the expiration or sooner termination
         of this Lease. If Tenant retains possession of the Premises or
         any part thereof after the termination of the Term without
         Landlord's express consent, Tenant shall pay Landlord rent at
         double the monthly rate specified in Section 1 for the time
         Tenant thus remains in possession and, in addition thereto,
         shall pay Landlord for all damages, excluding consequential
         damages, sustained by reason of Tenant's retention of
         possession. The provisions of this Section do not exclude
         Landlord's rights of re-entry or any other right hereunder,
         including without limitation, the right to remove Tenant
         through summary proceedings for holding over beyond the
         expiration of the Term of this Lease.

              Section 9.13. Assignment and Subletting. 

              (a)  Tenant covenants and agrees that neither this Lease
         nor the Term and estate hereby granted, nor any interest herein
         or therein, will be assigned, mortgaged, pledged, encumbered or
         otherwise transferred and that neither the Premises nor any
         part thereof will be encumbered in any manner by reason of any
         act or omission on the part of Tenant, or used or occupied or
         permitted to be used or occupied, by anyone other than Tenant,
         or for any use or purpose other than a Permitted Use, or be
         sublet (which term, without limitation, shall include granting
         of concessions, licenses and the like) in whole or in part
         without Landlord's consent which will not be unreasonably
         withheld or delayed.  The foregoing restrictions shall not be
         applicable to an assignment of this Lease or a subletting of
         the Premises by Tenant to any of the following parties
         (collectively called the "Related Occupants"):  a subsidiary
         wholly-owned by Tenant or to a controlling corporation, the
         stock of which is wholly-owned by the stockholders of Tenant,
         to any Affiliate of Tenant, to any purchaser of all or
         substantially all of Tenant's business or to any successor of
         Tenant by merger or consolidation provided, however, that any
         such Affiliate,  purchaser or successor shall have a net worth
         not less than that of Tenant immediately prior to such merger,
         consolidation or purchase.  It shall be a condition of the
         validity of any assignment, whether with the consent of
         Landlord or to a subsidiary or controlling corporation, that
         the assignee agree directly with Landlord, by written
         instrument in form satisfactory to Landlord, to be bound by all
         the obligations of Tenant hereunder including, without
         limitation, the covenant against further assignment and
         subletting.  No assignment or subletting shall relieve Tenant
         from its obligations hereunder and Tenant shall remain fully
         and primarily liable therefor.  Notwithstanding anything to the
         contrary contained herein, Landlord shall be entitled to
         collect (i) one hundred (100%) percent of any profit related to
         any assignment in connection with this Lease and (ii) fifty
         (50%) percent of any rent, income or profit derived from any
         sublease of any portion of the Premises in excess of Tenant's
         Base Subleasing Profit. 

              (b)  If this Lease be assigned, or if the Premises or
         any part thereof be sublet or occupied by anyone other than
         Tenant, Landlord may, whether or not it has consented to any
         such assignment, subletting or occupancy, at any time and from
         time to time collect rent and other charges from the assignee,
         subtenant or occupant, and apply the net amount collected to
         the rent and other charges herein reserved, but no such
         assignment, subletting, occupancy or collection shall be deemed
         a waiver of any breach of Section 8.1 (a), or the acceptance of
         the assignee, subtenant or occupant as a tenant or a release of
         Tenant from the further performance by Tenant of its
         obligations hereunder.  The consent by Landlord to an
         assignment or subletting shall in no way be construed to
         relieve Tenant or any successor from obtaining the express
         consent in writing of Landlord to any further assignment or
         subletting nor shall any such consent release, diminish or
         impair Tenant's continuing primary liability for performance of
         this Lease.  No assignment or subletting and no use of the
         Premises by a subsidiary wholly-owned by Tenant or controlling
         corporation of Tenant shall affect the Permitted Uses.

              (c)  In connection with any request by Tenant for
         Landlord's consent to a sublease as required under Section
         9.13(a), Tenant shall first submit to Landlord in writing:  (i)
         the name of the proposed subtenant, (ii) such information as to
         its financial responsibility and standing as Landlord may
         reasonably require, and (iii) all terms and provisions upon
         which the proposed subletting is to be made.  Upon receipt from
         Tenant of such requested information if Tenant is proposing a
         sublease of the entire Premises, Landlord shall have an option
         (the "Take Back Option") to be exercised in writing within
         thirty (30) days after its receipt from Tenant of such
         requested information, to cancel or terminate this Lease, as of
         the date set forth in Landlord's notice of exercise of the Take
         Back Option, which shall not be less than sixty (60) days nor
         more than one hundred twenty (120) days following the giving of
         such notice.  In the event Landlord shall exercise the Take
         Back Option, Tenant shall surrender possession of the entire
         Premises, on the date set forth in such notice in accordance
         with the provisions of this Lease relating to the surrender of
         the Premises at the expiration of the Term.  If Landlord
         exercises the Take Back Option, Landlord shall pay to Tenant
         the unamortized value of the tenant improvements located within
         the Premises. Notwithstanding anything to the contrary
         contained herein, Landlord's Take Back Option is applicable
         only if Tenant's request for Landlord's consent to a sublease
         involves a sublease of the entire Premises. 

              Section 9.14. Overloading and Nuisance. Tenant shall not
         injure, overload, deface or otherwise harm the Premises, commit
         any nuisance, permit the emission of any objectionable noise,
         vibration or odor, make, allow or suffer any waste or make any
         use of the Premises which is improper, offensive or contrary to
         any law or ordinance or which will invalidate any of Landlord's
         insurance.

                               SECTION 10
                            Casualty or Taking

              Section 10.1. Termination. In the event that greater than
         twenty-five (25) percent of the Building or the Lot shall be
         taken by any public authority or for any public use or
         destroyed by the action of any public authority (a "Taking")
         then this Lease may be terminated by either Landlord or Tenant
         effective on the effective date of the Taking. In the event
         that the Premises shall be destroyed or damaged by fire or
         casualty (a "Casualty") and if it will require in excess of 120
         days from the date of the Casualty to restore the Premises,
         this Lease may be terminated by either Landlord or Tenant by
         notice to the other within thirty days after the casualty. In
         the case of a Taking, such election, which may be made
         notwithstanding the fact that Landlord's entire interest may
         have been divested, shall be made by the giving of notice by
         Landlord or Tenant to the other within thirty (30) days after
         Landlord or Tenant, as the case may be, shall receive notice of
         the Taking.

              Section 10.2. Restoration. In the event of a Taking or a
         Casualty, unless Landlord or Tenant shall exercise an election
         to terminate provided in Section 10.1, this Lease shall
         continue in force and a just proportion of the Annual Rent and
         other charges hereunder, according to the nature and extent of
         the damages sustained by the Premises, but not in excess of an
         equitable portion of the net proceeds of any rental insurance
         recovered by Landlord, shall be abated until the Premises, or
         what may remain thereof, shall be put by Landlord in proper
         condition for use subject to zoning and building laws or
         ordinances then in existence, which, unless Landlord or Tenant
         has exercised its option to terminate pursuant to Section 10.1,
         Landlord covenants to do with reasonable diligence at
         Landlord's expense. Landlord's obligations with respect to
         restoration shall not require Landlord to expend more than the
         net proceeds of insurance recovered or damages awarded for such
         Casualty or Taking and made available for restoration by
         Landlord's mortgagees. "Net proceeds of insurance recovered or
         damages awarded" refers to the gross amount of such insurance
         or damages less the reasonable expenses of Landlord in
         connection with the collection of the same, including without
         limitation, fees and expenses for legal and appraisal services.

              Section 10.3. Award. Irrespective of the form in which
         recovery may be had by law, all rights to damages or
         compensation shall belong to Landlord except Tenant shall be
         entitled to claim relocation costs and a claim for the value of
         its improvements to the Premises provided that Tenant's claim
         does not diminish Landlord's claim or award.
                               SECTION 11
                                 Default

              Section 11.1. Events of Default. 

              If:  (a) Tenant shall default in the performance of any
         of its obligations to pay the Annual Fixed Rent, Additional
         Rent or any other sum payable hereunder and if such default
         shall continue for ten (10) days after notice from Landlord
         designating such default;

                   (b) if within thirty (30) days after notice from
         Landlord to Tenant specifying any other default or defaults
         Tenant has not commenced diligently to correct the default or
         defaults so specified or has not thereafter diligently pursued
         such' correction to completion;

                   (c) if any assignment for the benefit of creditors
         shall be made by Tenant;

                   (d) if Tenant's leasehold interest shall be taken
         on execution or other process of law in any action against
         Tenant;

                   (e) if a lien or other involuntary encumbrance is
         filed against Tenant's leasehold interest, and is not
         discharged or bonded over, as the case may be, within ten (10)
         days thereafter;

                   (f) if a petition is filed by Tenant for
         liquidation, or for reorganization or an arrangement or any
         other relief under any provision of the Bankruptcy Code as then
         in force and effect; or

                   (g) if an involuntary petition under any of the
         provisions of said Bankruptcy Code is filed against Tenant and
         such involuntary petition is not dismissed within thirty (30)
         days thereafter, then, and in any of such cases, Landlord and
         the agents and servants of Landlord lawfully may, in addition
         to and not in derogation of any remedies for any preceding
         breach of covenant, immediately or at any time thereafter and
         without demand or notice and with or without process of law
         (forcibly, if necessary) enter into and upon the Premises or
         any part thereof in the name of the whole, or mail a notice of
         termination addressed to Tenant, and repossess the same as of
         Landlord's former estate and expel Tenant and those claiming
         through or under Tenant and remove its and their effects
         without being deemed guilty of any manner of trespass and
         without prejudice to any remedies which might otherwise be used
         for arrears of rent or prior breach of covenant, and upon such
         entry or mailing as aforesaid this Lease shall terminate.
         Landlord, without notice to Tenant, may store Tenant's effects,
         and those of any person claiming through or under Tenant at the
         expense and risk of Tenant, and, if Landlord so elects, may,
         with notice to Tenant, sell such effects at public auction or
         private sale and apply the net proceeds to the payment of all
         sums due to Landlord from Tenant, if any, and pay over the
         balance, if any, to Tenant.

              Section 11.2. Remedies. In the event that this Lease is
         terminated under any of the provisions contained in Section
         11.1, Tenant shall pay forthwith to Landlord, as compensation,
         the present value of the excess of the total rent reserved for
         the residue of the Term over the fair market rental value
         (computed using a discount rate of eight (8%) percent) of the
         Premises for the residue of the Term. In calculating the rent
         reserved there shall be included, in addition to the Annual
         Fixed Rent and Additional Rent, the value of all other
         considerations agreed to be paid or performed by Tenant during
         the residue. As additional and cumulative obligations after any
         such termination, Tenant shall also pay punctually to Landlord
         all the sums and shall perform all the obligations which Tenant
         covenants in this Lease to pay and to perform in the same
         manner and to the same extent and at the same time as if this
         Lease had not been terminated. In calculating the amounts to be
         paid by Tenant pursuant to the preceding sentence, Tenant shall
         be credited with any amount paid to Landlord pursuant to the
         first sentence of this Section 11.2 and also with the net
         proceeds of any rent obtained by Landlord by reletting the
         Premises, after deducting all Landlord's reasonable expenses in
         connection with such reletting, including, without limitation,
         all repossession costs, brokerage commissions, fees for legal
         services and expenses of preparing the Premises for such
         reletting, it being agreed by Tenant that Landlord may (i)
         relet the Premises or any part or parts thereof for a term or
         terms which may at Landlord's option be equal to or less than
         or exceed the period which would otherwise have constituted the
         balance of the Term hereof and may grant such concessions and
         free rent as Landlord in its reasonable judgment considers
         advisable or necessary to relet the same and (ii) make such
         alterations, repairs and decorations in the Premises as
         Landlord in its reasonable judgment considers advisable or
         necessary to relet the same, and no action of Landlord in
         accordance with the foregoing or failure to relet or to collect
         rent under reletting shall operate or be construed to release
         or reduce Tenant's liability as aforesaid.  Landlord
         acknowledges and agrees to use reasonable efforts to relet the
         Premises provided, however, that any failure of Landlord to
         relet the Premises shall not constitute a default hereunder.

              Section 11.3. Remedies Cumulative. Except as otherwise
         expressly provided herein, any and all rights and remedies
         which Landlord may have under this Lease and at law and equity
         shall be cumulative and shall not be deemed inconsistent with
         each other, and any two or more of all such rights and remedies
         may be exercised at the same time to the greatest extent
         permitted by law.

              Section 11.4. Landlord's Right to Cure Defaults. At any
         time following ten (10) days' prior notice to Tenant (except in
         cases of emergency when no notice shall be required), Landlord
         may (but shall not be obligated to) cure any default by Tenant
         under this Lease, and whenever Landlord so elects, all costs
         and expenses incurred by Landlord, including reasonable
         attorneys' fees, in curing a default shall be paid by Tenant to
         Landlord as Additional Rent on demand, together with interest
         thereon at the rate provided in Section 11.7 from the date of
         payment by Landlord to the date of payment by Tenant.

              Section 11.5. Effect of Waivers of Default. Any consent
         or permission by Landlord to any act or omission which
         otherwise would be a breach of any covenant or condition
         herein, or any waiver by Landlord of the breach of any covenant
         or condition herein, shall not in any way be held or construed
         (unless expressly so declared) to operate so as to impair the
         continuing obligation of any covenant or condition herein, or
         otherwise operate to permit the same or similar acts or
         omissions except as to the specific instance. The failure of
         Landlord to seek redress for violation of, or to insist upon
         the strict performance of, any covenant or condition of this
         Lease shall not be deemed a waiver of such violation nor
         prevent a subsequent act, which would have originally
         constituted a violation, from having all the force and effect
         of an original violation. The receipt by Landlord of any Annual
         Rent hereunder with knowledge of the breach of any covenant of
         this Lease shall not be deemed to have been a waiver of such
         breach by Landlord or of any of Landlord's remedies on account
         thereof, including its right of termination for such default.

              Section 11.6. No Accord and Satisfaction. No acceptance
         by Landlord of a lesser sum than the Annual Fixed Rent,
         Additional Rent or any other sum then due shall be deemed to be
         other than on account of the earliest installment of such rent
         or charge due, unless Landlord elects by notice to Tenant to
         credit such sum against the most recent installment due. Any
         endorsement or statement on any check or any letter
         accompanying any check or payment as rent or other charge shall
         not be deemed an accord and satisfaction, and Landlord may
         accept such check or payment without prejudice to Landlord's
         right to recover the balance of such installment or pursue any
         other remedy under this Lease or otherwise.

              Section 11.7. Interest on Overdue Sums. If Tenant fails
         to pay Annual Fixed Rent, Additional Rent or other sums payable
         by Tenant to Landlord within ten (10) days of the due date
         thereof (i.e., the due date disregarding any requirement of
         notice from Landlord), the amount so unpaid shall bear interest
         at a variable rate (the "Delinquency Rate") equal to four
         percent (4%) in excess of the base rate (prime rate) of
         BankBoston from time to time in effect commencing with the
         eleventh (11th) day after the due date and continuing through
         the day on which payment of such delinquent payment with
         interest thereon is paid. If such rate is in excess of any
         maximum interest rate permissible under applicable law, the
         Delinquency Rate shall be the maximum interest rate permissible
         under applicable law.

              Section 11.8.  Cost and Expenses:  All costs and expenses
         incurred by or on behalf of Landlord (including, without
         limitation, attorneys' fees and expenses) in enforcing its
         rights hereunder or occasioned by any default of Tenant shall
         be paid by Tenant.

                               SECTION 12
                                Mortgages

              Section 12.1. Rights of Mortgage Holders. No Annual Fixed
         Rent, Additional Rent or any other charge which is paid more
         than one month prior to the due date thereof and payments made
         in violation of this provision shall (except to the extent that
         such payments are actually received by a mortgagee in
         possession or in the process of foreclosing its mortgage) be a
         nullity as against such mortgagee and Tenant shall be liable
         for the amount of such payments to such mortgagee, provided
         however, that the foregoing clause shall not apply to the
         Security Deposit and any mortgagee shall be governed by the
         terms and conditions of this Lease with respect to same.

              In the event of any act or omission by Landlord which
         would give Tenant the right to terminate this Lease or to claim
         a partial or total eviction, Tenant shall not exercise any such
         right (a) until it shall have given notice, in the manner
         provided in Section 13.1, of such act or omission to the holder
         of any mortgage encumbering the Premises whose name and address
         shall have been furnished to Tenant in writing, at the last
         address so furnished, and (b) until a reasonable period of time
         for remedying such act or omission shall have elapsed following
         the giving of such notice, provided that following the giving
         of such notice, Landlord or such holder shall, with reasonable
         diligence, have commenced and continued to remedy such act or
         omission or to cause the same to be rendered.  Notwithstanding
         the foregoing, such "reasonable period of time" shall not
         extend beyond thirty (30) days unless Landlord or such holder
         has commenced and diligently pursues to completion the remedy
         of such act or omission within said thirty (30) day period.
         The provisions contained in this paragraph shall not affect any
         of Tenant's rights to terminate this Lease under Section 3.7 of
         this Lease.

              In the event any proceedings are brought for the
         foreclosure of, or in the event of exercise of the power of
         sale under, any mortgage now or hereafter encumbering the
         Premises, Tenant shall attorn to the purchaser upon such
         foreclosure or sale or upon any grant of a deed in lieu of
         foreclosure and recognize such purchaser as Landlord under this
         Lease.

              Section 12.2. Lease Subordinate. At Landlord's election,
         this Lease, and all rights of Tenant hereunder, shall be
         subject and subordinate to all mortgages and/or ground leases
         which may now or hereafter affect the Property whether or not
         such mortgages or leases shall also cover other lands and/or
         buildings, to each and every advance made or hereafter to be
         made under such mortgages, and to all renewals, modifications,
         replacements and extensions of such mortgages and leases and
         all consolidations of such mortgages, provided that, with
         respect to any such mortgage or lease hereafter placed on the
         Property, Landlord shall deliver to Tenant an agreement, in
         form and substance reasonably acceptable to such holder or
         lessor and Tenant, by such holder or lessor to the effect that,
         subject to qualifications of the type set forth in the second
         sentence of paragraph (b) hereof, all of Tenant's rights
         hereunder shall be recognized by such holder or lessor.  Such
         subordination shall be automatic and without need for any
         additional action or documentation.  Without derogating from
         the foregoing, in confirmation of such subordination, and
         subject to the foregoing condition, Tenant shall promptly
         execute, acknowledge and deliver any instrument that Landlord,
         the holder of any such mortgage or the lessor under any such
         lease or any of their respective successors in interest may
         reasonably request to evidence such subordination.  Landlord
         agrees to request the holder of the existing mortgage on the
         Property to deliver an agreement, in form and substance
         acceptable to such holder, by such holder to the effect that,
         subject to the qualifications of the type set forth in the
         second sentence of paragraph (b) hereof, that such holder
         recognizes all of Tenant's rights hereunder provided that
         Tenant is not in default (beyond any applicable notice and
         grace period) of any of the terms, provisions, covenants,
         agreements and conditions to be observed, performed and
         complied with by Tenant under this Lease.  Any mortgage to
         which this Lease is, at the time referred to, subject and
         subordinate, is herein called "Superior Mortgage" and the
         holder of a Superior Mortgage is herein called "Superior
         Mortgagee"; and any lease to which this Lease is, at the time
         referred to, subject and subordinate is herein called "Superior
         Lease" and the lessor of a Superior Lease or its successor in
         interest, at the time referred to, is herein called "Superior
         Lessor".

                   (b)  If any Superior Mortgagee or Superior Lessor
         or the nominee or designee of any Superior Mortgagee or
         Superior Lessor shall succeed the rights of Landlord (for the
         purposes of this paragraph (b), the "Preceding Landlord") under
         this Lease, whether through possession or foreclosure action or
         delivery of a new lease or deed, or otherwise, then Tenant
         shall attorn to and recognize such party (herein called
         "Successor Landlord") so succeeding to the Preceding Landlord's
         rights as Tenant's landlord under this Lease and, upon such
         Successor Landlord's request, Tenant shall promptly execute and
         deliver any instrument that such Successor Landlord may
         reasonably request to evidence such attornment provided that
         such Successor Landlord gives Tenant a written agreement to
         accept Tenant's attornment and recognizes Tenant's rights under
         this Lease (subject to the qualifications) hereinafter set
         forth).  Upon such attornment, this Lease shall continue in
         full force and effect as a direct lease between the Successor
         Landlord and Tenant upon all of the terms, conditions and
         covenants as are set forth in this Lease, except that the
         Successor Landlord (unless formerly the landlord under this
         Lease or its nominee or designee) shall not be (a) liable in
         any way to Tenant for any act or omission, neglect or default
         on the part of the Preceding Landlord under this Lease, (b)
         responsible for any monies owing by or on deposit with the
         Preceding Landlord to the credit of Tenant (except for the
         Security Deposit to the extent that such Security Deposit is
         actually received by and is in possession of the Successor
         Landlord, which shall include the delivery of the Letter under
         the provisions of Section 13.8 of this Lease), (c) subject to
         any counterclaim or bound by any modification of this Lease
         subsequent to such Superior Mortgage or Lease which was not
         approved in writing by the Superior Mortgagee or Superior
         Lessor, or by any previous prepayment of Annual Fixed Rent or
         Additional Rent for more than one (1) month which was not
         approved in writing by the Superior Landlord's interest in the
         Property and the rents, income, receipts, revenues, issues and
         profits issuing from such Property, (f) responsible for the
         performance of any work to be done by the Preceding Landlord
         under this Lease to render the Premises ready for occupancy by
         the Tenant, (g) required to remove any person occupying the
         Premises or any part thereof, except if such person claims by
         through or under the Successor Landlord.  

                               SECTION 13
                          Miscellaneous Provisions

              Section 13.1. Notices from One Party to the
         Other. Whenever, by the terms of this Lease, notices, consents
         or approvals shall or may by given either to Landlord or to
         Tenant, such notices, consents or approvals shall be in writing
         and shall be delivered in hand, sent by registered or certified
         mail, return receipt requested, postage prepaid or sent by an
         overnight express courier service which provides evidence of
         delivery or attempted delivery;

                   If intended for Landlord, delivered or addressed to
         Landlord at the Original Address of Landlord (or to such other
         address as may from time to time hereafter be designated by
         Landlord by like notice).

                   If intended for Tenant, delivered or addressed to
         Tenant at the Original Address of Tenant until the Commencement
         Date and thereafter to the Premises (or to such other address
         or addresses as may from time to time hereafter be designated
         by Tenant by like notice).

                   All such notices shall be effective when delivered
         or tendered for delivery at the address to which the same were
         sent.

              Section 13.2. Lease Not to be Recorded; Notice of
         Lease. Tenant agrees that it will not record this Lease. If the
         Term of this Lease, including options, exceeds seven years,
         Landlord and Tenant agree that, on the request of either, they
         will enter and record a notice of lease in form reasonably
         acceptable to both parties.

              Section 13.3. Bind and Inure; Limitation of Landlord's
         Liability. The obligations of this Lease shall run with the
         land, and this Lease shall be binding upon and inure to the
         benefit of the parties hereto and their respective successors
         and assigns. No owner of the Lot shall be liable under this
         Lease except for breaches of Landlord's obligations occurring
         while owner of the Lot. The obligations of Landlord shall be
         binding upon the assets of Landlord which comprise the Lot but
         not upon other assets of Landlord. No individual, member,
         partner, trustee, stockholder, officer, director, employee or
         beneficiary of Landlord shall be personally liable under this
         Lease and Tenant shall look solely to Landlord's interest in
         the Lot in pursuit of its remedies upon an event of default
         hereunder, and the general assets of Landlord and its members,
         partners, trustees, stockholders, officers, employees or
         beneficiaries of Landlord shall not be subject to levy,
         execution or other enforcement procedure for the satisfaction
         of the remedies of Tenant.

              Section 13.4. Acts of God. In any case where either party
         hereto is required to do any act, delays caused by or resulting
         from acts of God, war, civil commotion, fire, flood or other
         casualty, labor difficulties, shortages of labor, materials or
         equipment, government regulations, unusually severe weather, or
         other causes beyond such party's reasonable control shall not
         be counted in determining the time during which work shall be
         completed, whether such time be designated by a fixed date, a
         fixed time or a "reasonable time", and such time shall be
         deemed to be extended by the period of such delay.

              Section 13.5. Landlord's Default. Landlord shall not be
         deemed to be in default in the performance of any of its
         obligations hereunder unless it shall fail to perform such
         obligations and unless within thirty (30) days after notice
         from Tenant to Landlord specifying such default Landlord has
         not commenced diligently to correct the default so specified or
         has not thereafter diligently pursued such correction to
         completion. Tenant shall have no right, for any default by
         Landlord, to offset or counterclaim against any rent due
         hereunder.  The provisions contained in this paragraph shall
         not affect any of Tenant's rights to terminate this Lease under
         Section 3.7 of this Lease.

              Section 13.6. Brokerage. Landlord shall pay a brokerage
         commission to Fallon, Hines & O'Connor, Inc. for the brokerage
         services rendered in connection with this Lease.  Tenant and
         Landlord warrant and represent to the other that neither has
         had any dealings with any broker or agent in connection with
         this Lease other than Fallon, Hines & O'Connor, Inc.  Tenant
         and Landlord agree to defend with counsel reasonably approved
         by the other, hold harmless and indemnify the other from and
         against any and all cost, expense or liability for any
         compensation, commissions and charges which may be asserted
         against the other as a result of the other's breach of this
         warranty.

              Section 13.7. Miscellaneous. This Lease shall be governed
         by and construed in accordance with the laws of the
         Commonwealth of Massachusetts. There are no prior oral or
         written agreements between Landlord and Tenant affecting this
         Lease.

              Section 13.8. Security Deposit.  In order to provide
         security against Tenant's default under Section 11.1(a) of the
         Lease (a "Monetary Default"), Tenant shall furnish Landlord on
         the Escrow Release Date with, and shall maintain in force and
         effect throughout the Term of this Lease, an irrevocable
         "clean" Letter of Credit which may provide for multiple draws,
         reductions and reinstatement of the stated amounts (hereinafter
         together with any renewal or substitution thereof in accordance
         with the provisions hereof referred to as "Letter") or cash
         ("Cash") in an amount equal to the "Applicable Amount" (as said
         term is hereinafter defined) from time to time required
         hereunder in the case of a Letter issued by Fleet Bank or a
         similar financial institution ("Issuer") in the greater Boston,
         Massachusetts area which is approved and accepted by Landlord
         (an "Approved Issuer").  Landlord shall deliver the Security
         Deposit to the holder of any first mortgage encumbering the
         Property and the Security Deposit will be held by the holder of
         any mortgage encumbering the Property for and during the Term
         and shall be returned to Tenant, within thirty (30) days after
         the expiration of the Term of this Lease provided there exists
         no Monetary Default.  As used herein, the term "Applicable
         Amount" shall mean (i) $750,000.00 beginning on the Escrow
         Release Date through the end of the 36th full calendar month
         immediately following the Commencement Date, (ii) provided that
         the "4th Lease Year Conditions" (as hereinafter defined are
         completely satisfied,  $375,000.00 during months 37 through 72
         of the Term, (iii) provided that the "7th Lease Year
         Conditions") (as hereinafter defined) are completely satisfied,
         $187,500.00 for the remainder of the Term of this Lease.  As
         used herein, the term "4th Lease year Conditions" shall mean
         that at the commencement of the fourth (4th) lease year of the
         Term of this Lease, based on a review of either Tenant's most
         recent 10Q or 10K statements filed with the Security Exchange
         Commission, Tenant has $10,000,000.00 in unrestricted cash,
         cash equivalents and marketable securities on hand and a
         "Current Assets" to "Current Liabilities", as said terms are
         hereinafter defined, ratio of 2.0:1.0.  The term "7th Lease
         Year Conditions" shall mean that at the commencement of the
         seventh (7th) lease year of the Term of this Lease, Tenant has
         $10,000,000.00 in unrestricted cash, cash equivalents and
         marketable securities on hand and a "Current Assets" to
         "Current Liabilities", as said terms are hereinafter defined,
         ratio of 2.0:1.0.  As used herein, the term "Current Assets"
         shall mean:  unrestricted cash, cash equivalents, marketable
         securities, accounts receivable, inventories, prepaid expenses
         and other current assets under generally accepted accounting
         practices.  "Current Liabilities" shall mean:  accounts
         payable, accrued royalties, accrued professional fees, accrued
         incentive compensation, accrued restructuring costs, current
         portion of deferred revenue, current maturities of long term
         debt and other accrued expenses under generally accepted
         accounting practices.

              Tenant shall have the right to call upon Landlord to
         apply all or any part of the Security Deposit to cure any
         Monetary Default.  If all or any part of the Security Deposit
         is applied to cure the Monetary Default, Tenant shall within
         ten (10) days from any request by Landlord restore the Security
         Deposit to the Applicable Amount, and notwithstanding the
         occurrence of a Monetary Default, Tenant shall not be deemed in
         default hereunder unless and until Tenant shall fail to restore
         the amount of the Security Deposit.

              The Security Deposit shall be delivered by Landlord to
         Landlord's successor in interest under the Lease and upon any
         such delivery and the acknowledgment of such successor that
         such successor holds the Security Deposit under the terms and
         conditions of the Lease, Tenant shall release Landlord herein
         named of any and all liability with respect to the Security
         Deposit, its application and return.

              The Letter shall be addressed to and for the benefit of
         the Landlord under this Lease from time to time and be in form
         and substance satisfactory to Landlord in its reasonable
         discretion.  In the event of a Monetary Default by Tenant under
         this Lease, Landlord may draw upon an amount necessary to cure
         the Monetary Default upon certification by Landlord to the
         Issuer that Landlord is entitled to apply all or any part of
         the proceeds of the Letter to the extent required to cure the
         Monetary Default.

              In the event of any Monetary Default by Tenant under this
         Lease, Landlord shall provide Tenant with two (2) Business Days
         written notice prior to drawing down on the Letter.  In the
         event of any Monetary Default by Tenant under this Lease, if
         Landlord applies any part of the proceeds of the Letter or the
         Cash to cure any default of Tenant, Tenant shall, upon demand,
         cause the Letter or the Cash to be replenished and reinstated
         to the extent of the amount so drawn upon and applied in order
         that Landlord shall, at all times, have the full Applicable
         Amount of the Letter or the Cash available for the purposes
         hereof during the Term of this Lease.  The Letter shall, in
         each instance, and for each year of the Term of this Lease, be
         in effect and, at Tenant's sole cost and expense, be renewed by
         Tenant and decreased to the required Applicable Amount in no
         event later than sixty (60) days prior to its date of
         expiration.  Tenant's failure to maintain the Letter in force
         and effect in the Applicable Amounts during the periods of time
         required hereunder shall, if such failure continues for more
         than ten (10) days after notice thereof from Landlord,
         constitute a default under this Lease.  If, on or before the
         sixtieth (60th) day prior to the expiration date of a Letter,
         Tenant shall have failed to deliver to Landlord an original
         fully executed renewal or extension of the Letter (or a
         substitute letter of credit from an Approved Issuer), in each
         case, having a term of at least one year and such failure shall
         continue for more than ten (10) days after Landlord has given
         Tenant notice of such failure, Landlord, at its option, may,
         but shall not be required to without further notice to Tenant,
         draw down upon the Letter in its entirety in which event
         Landlord may, in addition to all other rights and remedies
         which it may have on account of such default, treat all sums
         drawn under such Letter as a Cash Security Deposit governed by
         and to be applied and/or retained by Landlord pursuant to the
         provisions of this paragraph.  All references herein to the
         Letter shall also mean and include all renewals and
         replacements thereof and all modifications and extensions
         thereof.  Any renewal, extension or substitution of a Letter
         shall be in form and substance satisfactory to Landlord, in its
         reasonable discretion, and shall be issued by an Approved
         Issuer.  Landlord will not unreasonably delay or withhold
         approval of the form of any substitute Letter which is in the
         same form as that previously approved by Landlord.  If the
         Property is sold and if the purchaser and seller together
         request in writing that Tenant obtain a modification to a
         Letter designating the purchaser as the "beneficiary"
         thereunder in substitution for the then named beneficiary,
         Tenant agrees to promptly obtain and deliver such amendment to
         such purchaser at purchaser's sole cost and expense.  Tenant
         hereby agrees that all costs and expenses involved in obtaining
         and maintaining the Letters contemplated by this paragraph
         shall be borne solely and exclusively by Tenant.
         Notwithstanding anything to the contrary contained herein, if
         Tenant fails to remove Tenant's Removable Property as required
         hereunder at such time as Tenant surrenders and yields up its
         right and interest in the Premises, then Landlord shall have
         the right to draw down all or any portion of the Security
         Deposit necessary to cover the costs and expenses associated
         with the removal of Tenant's Removable Property.

              Section 13.9. Park Common Expenses. 

              (a)  Tenant shall pay to Landlord as Additional Rent
         monthly with each payment of Annual Fixed Rent an amount equal
         to one twelfth (1/12th) of the annual amount of the "Lot's
         Allocable Share" (as defined in Section 13.9(b))of the "Park
         Common Expenses" (as said term is hereinafter defined).  As
         used herein, the term "Park Common Expenses" shall mean "Common
         Expenses" as said term is defined in the Park Covenants;
         provided, however, the term "Park Common Expenses" shall not
         include any costs relating to the remediation of any hazardous
         materials on the Lot and the Leasehold Parking Area in
         connection with closure of the landfill on the Landfill Lot.
         Landlord shall use diligent efforts to cause the owner of the
         Park Common Property to maintain and repair the Park Common
         Property insofar as it services the Premises in good operating
         condition and repair.  As used herein, the term "Park Common
         Property" shall mean the "Infrastructure Easement Areas" and
         the "Common Land", as such terms are defined in the Park
         Covenants.  

              (b)  As used in this Lease, the term "Lot's Allocable
         Share" shall mean a percentage equal to that percentage which
         is attributable to the Premises under the Park Covenants in
         determining the Premises' share of Common Expenses under the
         Park Covenants but in no event shall the Lot's Allocable Share
         ever exceed ten (10%) percent.

              (c)  At the beginning of every calendar year and at the
         commencement of the Term, Landlord shall deliver to Tenant its
         good faith estimate of the expenses (i.e. the Park Common
         Expenses) referenced in this Section 13.9 for such year, and
         Tenant shall make monthly payments based on that amount. As
         soon as practicable after the end of each calendar year,
         Landlord shall render a statement (the "Park Common Expense
         Statement") showing for the preceding calendar year or fraction
         thereof, as the case may be, the actual annual expenses for
         such matters for such year or fraction, and thereupon any
         balance owed by Tenant or excess paid by Tenant under this
         Section shall be paid to Landlord or credited to Tenant, as the
         case may be, on the next rent payment date.  Upon request of
         Tenant made within ninety (90) days after delivery of the Park
         Common Expense Statement, Tenant shall have the right to audit
         Landlord's books and records with respect to such Park Common
         Expense Statement.  If such audit discloses an overstatement of
         Park Common Expenses of more than five (5%) percent, Landlord
         shall reimburse Tenant for Tenant's reasonable out-of-pocket
         expenses for such audit. Landlord shall credit to Tenant the
         amount of any overpayment of Park Common Expenses by Tenant
         against subsequent obligations of Tenant with respect to Park
         Common Expenses (or refund such overpayment if the Term of this
         Lease has ended and Tenant has no further obligation to
         Landlord).

              Section 13.10.  Leasehold Parking Area.  It is expressly
         understood and agreed by and between Landlord and Tenant that
         this Lease, as to the Leasehold Parking Area, is a sublease and
         is subject and subordinate to the Ground Lease with respect to
         the Leasehold Parking Area and that no right, power or
         privilege granted to Tenant hereunder with respect to the
         Leasehold Parking Area may be exercised or enjoyed by Tenant
         and no term, covenant or condition of this Lease insofar as it
         relates to the Leasehold Parking Area benefiting Tenant shall
         be operative if and to the extent that such exercise, enjoyment
         or operation would not be permitted by or would violate or be
         in conflict with any term, covenant or condition of the Ground
         Lease.  Without limiting the generality of the foregoing, it is
         expressly understood and agreed that all rights of Tenant in
         and to any eminent domain awards in any way related to the
         Leasehold Parking Area shall be, and is hereby expressly made,
         subject and subordinate to the rights of the Landlord under the
         Ground Lease.  Landlord covenants and agrees that Landlord will
         not violate any of the terms, covenants or conditions of the
         Ground Lease.  The cost of any and all insurance required to be
         carried by Landlord under the Ground Lease or which Landlord
         carries in connection with the Ground Lease shall be included
         in the costs payable by Tenant as Additional Rent under this
         Lease.  From and after the Term Commencement Date and to the
         maximum extent, this agreement may be made effective according
         to law, Tenant agrees to indemnify and save harmless the Town
         of Framingham, as landlord under the Ground Lease (the "Ground
         Lease Landlord") from and against all claims of whatever nature
         arising from any act, omission or negligence of Tenant,
         Tenant's contractors, licensees, agents, servants, employees or
         customers, or anyone claiming by, through or under Tenant so
         long as Tenant or any occupant claiming under Tenant is in
         occupancy or is using any part of the entire Leasehold Parking
         Area where such accident, injury or damage results or is
         claimed to have resulted from any act, omission or negligence
         on the part of Tenant or Tenant's contractors, licensees,
         agents, servants, employees or customers or anyone claming by,
         through or under Tenant.  The foregoing indemnity and hold
         harmless agreement shall include indemnity against all costs
         and expenses and liabilities incurred in or in connection with
         any claim or proceeding brought thereon and the defense thereof
         with counsel acceptable to the Ground Lease Landlord.  To the
         maximum extent, this agreement may be made effective according
         to law, Tenant agrees to use and occupy the Leasehold Parking
         Area and any other part of the entire Leasehold Parking Area
         which the Tenant is permitted to use hereunder at Tenant's own
         risk and the Ground Lease Landlord shall have no responsibility
         or liable for any loss or damage to fixtures or other personal
         property of Tenant or any person claiming by, through or under
         Tenant.

              Section 13.11.  Hazardous Materials.  Tenant shall not
         (either with or without negligence) cause or permit the escape,
         disposal, release or threat of release of any biologically or
         chemically active or other Hazardous Materials (as said term is
         hereafter defined) on, in, upon or under the Property or the
         Premises except in compliance with all laws, rules,
         regulations, ordinances and codes, including, without
         limitation, the Environmental Laws.  Tenant shall not allow the
         generation, storage, use, disposal or transfer of such
         Hazardous Materials in any manner not sanctioned by law or by
         the highest standards prevailing in the industry for the
         generation, storage, use, disposal and transfer of such
         Hazardous Materials, nor allow to be brought into the Property
         any such Hazardous Materials except for those certain chemicals
         used in the ordinary course of Tenant's business and more
         particularly identified on Exhibit O attached hereto.  Tenant
         shall update the list of Tenant's Chemicals on an annual basis
         and/or as Landlord reasonably requests.  If any lender or
         governmental agency shall ever require testing to ascertain
         whether or not there has been any release of Hazardous
         Materials, then the reasonable costs thereof shall be
         reimbursed by Tenant to Landlord upon demand as additional
         charges but only if such requirement applies to the Premises or
         may be the result of the acts or omissions of Tenant.  In
         addition, Tenant shall execute affidavits, representations and
         the like, from time to time, at Landlord's request concerning
         Tenant's best knowledge and belief regarding the presence of
         Hazardous Materials on the Premises.  

              The Tenant shall, at its own expense, remove, clean up,
         remedy and dispose of (in compliance with all applicable laws,
         rules and regulations) all Hazardous Materials generated or
         released by the Tenant or its officers, directors, employees,
         contractors, servants, invitees, agents or any other person
         acting under Tenant during the Term of this Lease (or during
         such term as the Tenant is in occupancy or possession of any
         part of the Premises, the Building or the Property) at or from
         the Premises, the Building or the Property in compliance with
         all Environmental Laws (as said term is hereafter defined) and
         further, shall remove, clean up, remedy and dispose of all
         Hazardous Materials located at, upon, under, within or in the
         Premises, the Building or the Property generated by or
         resulting from its operations, activities or processes during
         the term of this Lease (or such other periods of time as the
         Tenant may be in occupancy or in possession of the Premises or
         any portion of the Property or Building), in compliance with
         all Environmental Laws.  In performing its obligations
         hereunder, the Tenant shall use best efforts to avoid
         interference with the use and enjoyment of the Building and
         the Property by other tenants and occupants thereof.  The
         provisions hereof shall survive expiration or termination of
         this Lease.  

              The Tenant shall indemnify, defend and save harmless the
         Landlord and its members, officers, directors, shareholders,
         employees, contractors, servants, invitees, representatives
         and agents from and against all loss, costs, damages, claims,
         proceedings, demands, liabilities, penalties, fines and
         expenses, including without limitation, reasonable fees and
         costs for attorneys' fees, consultants' fees, litigation costs
         and clean-up costs asserted<PAGE>






         against or incurred by the Landlord, its members, officers,
         directors, shareholders, employees, contractors, servants,
         invitees representatives or agents at any time by reason of or
         arising out of (i) any release or threat of release of any
         Hazardous Materials at, in, upon, under or from the Premises,
         the Building or the Property where such release or threat of
         release is the result of or alleged to result from the acts or
         omissions of the Tenant or its agents, servants, employees,
         contractors or invitees, or (ii) any violation or alleged
         violation of any Environmental Laws governing Hazardous
         Materials where such violation or alleged violation is the
         result of or alleged to result from the acts or omissions of
         the Tenant or its agents, servants, employees, contractors,
         invitees, or any other person acting under Tenant. The
         indemnities set forth in this Section shall survive expiration
         or termination of this Lease. 

              In addition to the requirements set forth above, the
         Tenant shall, within ten (10) days of receipt, provide to the
         Landlord copies of any inspection or other reports,
         correspondence, documentation, orders, citations, notices,
         directives, or suits from or by any governmental authority or
         insurer regarding non-compliance with or potential or actual
         violation of Environmental Laws.  The Landlord hereby
         expressly reserves the right to enter the Premises and all
         other portions of the Building and the Property in order to
         perform inspections and testing of the air, soil and
         groundwater for the presence or existence of Hazardous
         Materials.

              As used herein, the term "Hazardous Materials" shall mean
         and include, without limitation, any material or substance
         which is (i) petroleum, (ii) asbestos, (iii) designated as a
         "hazardous substance" pursuant to Section 311 of the Federal
         Water Pollution Control Act, 33 U.S.C. SS 1251 et seq. (33
         U.S.C. SS 1321) or listed in SS 307 of the Federal Water
         Pollution Control Act (33 U.S.C. SS 1317), (iv) defined as a
         "hazardous waste" pursuant to Section 1004 of the Resource
         Conservation and Recovery Act, 42 U.S.C. SS 6901 et seq. (42
         U.S.C. SS 6903), (v) defined as a "hazardous substance"
         pursuant to Section 101 of the Comprehensive Environmental
         Response, Compensation, and Liability Act, 42 U.S.C. SS 9601 et
         seq. (42 U.S.C. SS 9601), as amended and regulations
         promulgated thereunder, or (vi) defined as "oil" or a
         "hazardous waste", a "hazardous substance", a "hazardous
         material" or a "toxic material" under any other law, rule or
         regulation applicable to the Property, including, without
         limitation, Chapter 21E of the Massachusetts General Laws, as
         amended and the regulations promulgated thereunder.  As used
         herein, the term "Environmental Laws" shall mean, without
         limitation, each and every law, rule, order, statute or
         regulation described above in this Section, together with (i)
         any amendments thereto, or regulations promulgated thereunder
         and (ii) any other laws pertaining to the protection of the
         environment or governing the use, release, storage, generation
         or disposal of Hazardous Materials, whether now existing or
         hereafter enacted or promulgated.

              Section 13.12.  Landlord's Holdover Contribution.  If the
         Commencement Date should fail to occur on or before the
         Anticipated Term Commencement Date as such date may be extended
         by the Force Majeure Extension, then Landlord shall pay
         Landlord's Holdover Contribution to Tenant on the first day of
         each month in arrears commencing on the first day of the month
         next succeeding the Anticipated Term Commencement Date, as
         extended; provided, however, in no event shall Landlord have
         any obligation to pay any payment of Landlord's Holdover
         Contribution unless no default of Tenant shall have occurred
         and be continuing under this Lease.  Landlord's obligation to
         continue to pay Landlord's Holdover Contribution to Tenant
         shall cease upon the earlier to occur of the Commencement Date
         or the date of any termination of this Lease.


              WITNESS the execution hereof under seal as of the day and
         year first above written.


              Landlord:                NDNE 9/90 CORPORATE CENTER LLC



                                       By:  /s/ 
                                       ________________________

                                       Its:  Executive Vice President
                                       ________________________




              Tenant:                  AQUILA BIOPHARMACEUTICALS, INC. 



                                       By: /s/ Alison Taunton-Rigby
                                       ________________________

                                       Its:  President
                                       ________________________






         NDNE0023/15
         September 26, 1997

         The Company agrees to file copies of any exhibits to the Lease with
         the Commission upon request.