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                               NEUROMEDICA, INC.

            1992 EMPLOYEE, DIRECTOR AND CONSULTANT STOCK OPTION PLAN

1. DEFINITIONS.

     Unless otherwise specified or unless the context otherwise requires, the
following terms, as used in this Neuromedica, Inc. 1992 Employee, Director and
Consultant Stock Option Plan, have the following meanings:

          ADMINISTRATOR means the Board of Directors, unless it has delegated
     power to act on its behalf to a committee. (See Article 4)

          AFFILIATE means a corporation which, for purposes of Section 424 of
     the Code, is a parent or subsidiary of the Company, direct or indirect.

          BOARD OF DIRECTORS means the Board of Directors of the Company.

          CODE means the United States Internal Revenue Code of 1986, as
     amended.

          COMMITTEE means the Committee to which the Board of Directors has
     delegated power to act under or pursuant to the provisions of the Plan.

          COMMON STOCK means shares of the Company's common stock, $.01 par
     value.

          COMPANY means Neuromedica, Inc. a Massachusetts corporation.

          DISABILITY or DISABLED means permanent and total disability as defined
     in Section 22(e)(3) of the Code.

          FAIR MARKET VALUE of a Share of Common Stock means:

               (1) If the Common Stock is listed on a national securities
          exchange or traded in the over-the-counter market and sales prices are
          regularly reported for the Common Stock, the average of the closing or
          last prices of the Common Stock on the Composite Tape or other
          comparable reporting system for the ten (10)


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          consecutive trading days immediately preceding the applicable date;

               (2) If the Common Stock is not traded on a national securities
          exchange but is traded on the over-the-counter market, if sales prices
          are not regularly reported for the Common Stock for the ten (10) days
          referred to in clause (1), and if bid and asked prices for the Common
          Stock are regularly reported, the average of the mean between the bid
          and the asked price for the Common Stock at the close of trading in
          the over-the-counter market for the ten (10) days on which Common
          Stock was traded immediately preceding the applicable date; and

               (3) If the Common Stock is neither listed on a national
          securities exchange nor traded in the over-the-counter market, such
          value as the Administrator, in good faith, shall determine.

          ISO means an option meant to qualify as an incentive stock option
     under Code Section 422.

          KEY EMPLOYEE means an employee of the Company or of an Affiliate
     (including, without limitation, an employee who is also serving as an
     officer or director of the Company or of an Affiliate), designated by the
     Administrator to be eligible to be granted one or more Options under the
     Plan.

          NON-QUALIFIED OPTION means an option which is not intended to qualify
     as an ISO.

          OPTION means an ISO or Non-Qualified Option granted under the Plan.

          OPTION AGREEMENT means an agreement between the Company and a
     Participant executed and delivered pursuant to the Plan.

          PARTICIPANT means a Key Employee, director or consultant to whom one
     or more Options are granted under the Plan. As used herein, "Participant"
     shall include "Participant's Survivors" where the context requires.

          PARTICIPANT'S SURVIVORS means a deceased Participant's legal
     representative and/or any person or persons who acquired the Participant's
     rights to an Option by will or by the laws of descent and distribution.


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          PLAN means this Neuromedica, Inc. 1992 Employee, Director and
     Consultant Stock Option Plan.

          SHARES means shares of the Common Stock as to which Options have been
     or may be granted under the Plan or any shares of capital stock into which
     the Shares are changed or for which they are exchanged within the
     provisions of Paragraph 3 of the Plan. The Shares issued upon exercise of
     Options granted under the Plan may be authorized and unissued shares or
     shares held by the Company in its treasury, or both.

2. PURPOSES OF THE PLAN.

     The Plan is intended to encourage ownership of Shares by Key Employees,
directors and certain consultants to the Company in order to attract such
people, to induce them to work for the benefit of the Company or of an Affiliate
and to provide additional incentive for them to promote the success of the
Company or of an Affiliate. The Plan provides for the issuance of ISOs and
Non-Qualified Options.

3. SHARES SUBJECT TO THE PLAN.

     The number of Shares subject to this Plan as to which Options may be
granted from time to time shall be [Number of Shares], or the equivalent of
such number of Shares after the Administrator, in its sole discretion, has
interpreted the effect of any stock split, stock dividend, combination,
recapitalization or similar transaction in accordance with Paragraph 16 of
the Plan.

     If an Option ceases to be "outstanding", in whole or in part, the Shares
which were subject to such Option shall be available for the granting of
other Options under the Plan. Any Option shall be treated as "outstanding"
until such Option is exercised in full, or terminates or expires under the
provisions of the Plan, or by agreement of the parties to the pertinent
Option Agreement.

4. ADMINISTRATION OF THE PLAN.

     The Administrator of the Plan will be the Board of Directors, except to the
extent the Board of Directors delegates its authority to a Committee of the
Board of Directors. Following the date on which the Common Stock is registered
under the Securities and Exchange Act of 1934, as amended (the "1934 Act"), the
Plan is intended to comply in all respects with Rule

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16b-3 or its successors, promulgated pursuant to Section 16 of the 1934 Act with
respect to Participants who are subject to Section 16 of the 1934 Act, and any
provision in this Plan with respect to such persons contrary to Rule 16b-3 shall
be deemed null and void to the extent permissible by law and deemed appropriate
by the Administrator. Subject to the provisions of the Plan, the Administrator
is authorized to:

     a.   Interpret the provisions of the Plan or of any Option or Option
          Agreement and to make all rules and determinations which it deems
          necessary or advisable for the administration of the Plan;

     b.   Determine which employees of the Company or of an Affiliate shall be
          designated as Key Employees and which of the Key Employees, directors
          and consultants shall be granted Options;

     c.   Determine the number of Shares for which an Option or Options shall be
          granted; and

     d.   Specify the terms and conditions upon which an Option or Options may
          be granted;

provided, however, that all such interpretations, rules, determinations, terms
and conditions shall be made and prescribed in the context of preserving the tax
status under Code Section 422 of those Options which are designated as ISOs.
Subject to the foregoing, the interpretation and construction by the
Administrator of any provisions of the Plan or of any Option granted under it
shall be final, unless otherwise determined by the Board of Directors, if the
Administrator is other than the Board of Directors.

5. ELIGIBILITY FOR PARTICIPATION.

     The Administrator will, in its sole discretion, name the Participants in
the Plan, provided, however, that each Participant must be a Key Employee,
director or consultant of the Company or of an Affiliate at the time an
Option is granted. Notwithstanding any of the foregoing provisions, the
Administrator may authorize the grant of an Option to a person not then an
employee, director or consultant of the Company or of an Affiliate. The
actual grant of such Option, however, shall be conditioned upon such person
becoming eligible to become a Participant at or prior to the time of the
execution of the Option Agreement evidencing such Option. ISOs may be granted
only to Key Employees. Non-Qualified Options may be granted to any Key
Employee, director or consultant of the Company or an Affiliate. The granting
of any Option to any individual shall

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neither entitle that individual to, nor disqualify him or her from,
participation in any other grant of Options.

6. TERMS AND CONDITIONS OF OPTIONS.

     Each Option shall be set forth in writing in an Option Agreement, duly
executed by the Company and by the Participant. The Administrator may provide
that Options be granted subject to such conditions as the Administrator may deem
appropriate including, without limitation, subsequent approval by the
stockholders of the Company of this Plan or any amendments thereto. The Option
Agreements shall be subject to at least the following terms and conditions:

     A.   NON-QUALIFIED OPTIONS: Each Option intended to be a Non-Qualified
          Option shall be subject to the terms and conditions which the
          Administrator determines to be appropriate and in the best interest of
          the Company, subject to the following minimum standards for any such
          Non-Qualified Option:

          a.   Option Price: The option price (per share) of the Shares covered
               by each Option shall be determined by the Administrator but shall
               not be less than the par value per share of Common Stock.

          b.   Each Option Agreement shall state the number of Shares to which
               it pertains;

          c.   Each Option Agreement shall state the date or dates on which it
               first is exercisable and the date after which it may no longer be
               exercised, and may provide that the Option rights accrue or
               become exercisable in installments over a period of months or
               years, or upon the occurrence of certain conditions or the
               attainment of stated goals; and

          d.   Exercise of any Option may be conditioned upon the Participant's
               execution of a Share purchase agreement in form satisfactory to
               the Administrator providing for certain protections for the
               Company and its other shareholders including requirements that:

               i.   The Participant's or the Participant's Survivors' right to
                    sell the Shares may be restricted; and


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              ii.  The Participant or the Participant's Survivors may be
                   required to execute letters of investment intent and must
                   also acknowledge that the Shares will bear legends noting
                   any applicable restrictions.

     B.  ISOs: Each Option intended to be an ISO shall be issued only to a
         Key Employee and be subject to at least the following terms and
         conditions, with such additional restrictions or changes as the
         Administrator determines are appropriate but not in conflict with
         Code Section 422 and relevant regulations and rulings of the
         Internal Revenue Service:

         a.  Minimum standards: The ISO shall meet the minimum standards
             required of Participants who are granted Non-Qualified Options,
             as described above, except clause (a) thereunder.

         b.  Option Price: Immediately before the Option is granted, if the
             Participant owns, directly or by reason of the applicable
             attribution rules in Code Section 424(d):

             i.  Ten percent (10%) OR LESS of the total combined voting power
                 of all classes of share capital of the Company or an
                 Affiliate, the Option price (per share) of the Shares
                 covered by each Option shall not be less than one hundred
                 percent (100%) of the Fair Market Value (per share) of the
                 Shares on the date of the grant of the Option.

             ii. More than ten percent (10%) of the total combined voting
                 power of all classes of share capital of the Company or an
                 Affiliate, the Option price (per share) of the Shares
                 covered by each Option shall not be less than one hundred
                 ten percent (110%) of the said Fair Market Value on the date
                 of grant.

         c.  Term of Option: For Participants who own

             i.  Ten percent (10%) OR LESS of the total combined voting
                 power of all classes of share capital of the Company or an
                 Affiliate, each Option shall terminate not more than ten
                 (10) years from the date of the grant or at such earlier
                 time as the Option Agreement may provide;


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             ii. More than 10% of the total combined voting power of all
                 classes of share capital of the Company or an Affiliate,
                 each Option shall terminate not more than five (5) years
                 from the date of the grant or at such earlier time as the
                 Option Agreement may provide.

         d.  Medium of Payment: The Option price shall be payable upon the
             exercise of the Option and only in such form as the
             Administrator determines and as is permitted by Section 422 of
             the Code.

         e.  Limitation on Yearly Exercise: The Option Agreements shall
             restrict the amount of Options which may be exercisable in any
             calendar year (under this or any other ISO plan of the Company
             or an Affiliate) so that the aggregate Fair Market Value
             (determined at the time each ISO is granted) of the stock with
             respect to which ISOs are exercisable for the first time by the
             Participant in any calendar year does not exceed one hundred
             thousands dollars ($100,000), provided that this subparagraph
             (e) shall have no force or affect if its inclusion in the Plan
             is not necessary for Options issued as ISOs to qualify as ISOs
             pursuant to Section 422(d) of the Code.

         f.  Limitation on Grant of ISOs: No ISOs shall be granted after
             October 31, 2002, the date which is the EARLIER of ten (10)
             years from the date of the adoption of the Plan by the Company
             and the date of the approval of the Plan by the shareholders of
             the Company.

7.  EXERCISE OF OPTION AND ISSUE OF SHARES.

    An Option (or any part or installment thereof) shall be exercised by
giving written notice to the Company at its principal office address,
together with provision for payment of the purchase price in accordance with
this paragraph for the shares as to which such Option is being exercised, and
upon compliance with any other condition(s) set forth in the Option
Agreement. Such written notice shall be signed by the person exercising the
Option, shall state the number of Shares with respect to which the Option is
being exercised and shall contain any representation required by the Plan or
the Option Agreement. Full payment of the purchase price for the Shares as to
which such Option is being exercised shall be made (a) in United States
dollars in cash or by check, or (b) at the discretion of the Administrator,
through delivery of shares of Common Stock having


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a fair market value equal as of the date of the exercise to the cash exercise
price of the Option, determined in good faith by the Administrator, or (c) at
the discretion of the Administrator, by delivery of the grantee's personal
recourse note bearing interest payable not less than annually at no less than
100% of the applicable Federal rate, as defined in Section 1274(d) of the
Code, (d) at the discretion of the Administrator in accordance with a
so-called cashless exercise plan established with a securities brokerage firm
and approved by the Administrator, or (e) at the discretion of the
Administrator, by any combination of (a), (b), (c) and (d) above.
Notwithstanding the foregoing, the Administrator shall accept only such
payment on exercise of an ISO as is permitted by Section 422 of the code.

    The Company shall then reasonably promptly deliver the Shares as to which
such Option was exercised to the Participant (or to the Participant's
Survivors, as the case may be). In determining what constitutes "reasonably
promptly," it is expressly understood that the delivery of the Shares may be
delayed by the Company in order to comply with any law or regulation which
requires the Company to take any action with respect to the Shares prior to
their issuance. The Shares shall, upon delivery, be evidenced by an
appropriate certificate or certificates for fully paid, non-assessable Shares.

    The Administrator shall have the right to accelerate the date of exercise
on any installment of any Option; provided that the Administrator shall not
accelerate the exercise date of any installment of any Option granted to any
Key Employee as an ISO (and not previously converted into a Non-Qualified
Option pursuant to paragraph 19) if such acceleration would violate the
annual vesting limitation contained in Section 422(d) of the Code, as
described in paragraph 6B.(e).

8.  RIGHTS AS A SHAREHOLDER.

    No Participant to whom an Option has been granted shall have rights as a
shareholder with respect to any Shares covered by such Option, except after
due exercise of the Option and tender of the full purchase price for the
Shares being purchased pursuant to such exercise and registration of the
Shares in the Company's share register in the name of the Participant.

9.  ASSIGNABILITY AND TRANSFERABILITY OF OPTIONS.

    By its terms, an Option granted to a Participant shall not be
transferable by the Participant other than by will or by the laws of descent
and distribution and shall be exercisable, during the Participant's lifetime,
only by such Participant (or by his


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or her legal representative). Such Option shall not be assigned, pledged or
hypothecated in any way (whether by operation of law or otherwise) and shall
not be subject to execution, attachment or similar process. Any attempted
transfer, assignment, pledge, hypothecation or other disposition of any
Option or of any rights granted thereunder contrary to the provisions of this
Plan, or the levy of any attachment or similar process upon an Option, shall
be null and void.

10. EFFECT OF TERMINATION OF SERVICE OTHER THAN "FOR CAUSE".

    Except as otherwise provided in the pertinent Option Agreement, in the
event of a termination of service (whether as an employee, director or
consultant) with the Company or an Affiliate before the Participant has
exercised all Options, the following rules apply:

    a.  A Participant who ceases to be an employee, director or consultant of
        the Company or of an Affiliate (for any reason other than termination
        "for cause", Disability, or death for which events there are special
        rules in Paragraphs 11, 12, and 13, respectively), may exercise any
        Option granted to him or her to the extent that the right to purchase
        Shares has accrued on the date of such termination of service, but
        only within such term as the Administrator has designated in the
        pertinent Option Agreement.

    b.  In no event may an Option Agreement provide, if the Option is
        intended to be an ISO, that the time for exercise be later than three
        (3) months after the Participant's termination of employment.

    c.  The provisions of this paragraph, and not the provisions of Paragraph
        12 or 13, shall apply to a Participant who subsequently becomes
        disabled or dies after the termination of employment, director status
        or consultancy, provided, however, in the case of a Participant's
        death within three (3) months after termination of employment,
        director status or consulting, the Participant's Survivors may exercise
        the Option within one (1) year after the date of the Participant's
        death, but in no event after the date of expiration of the term of
        the Option.

    d.  Notwithstanding anything herein to the contrary, if subsequent to a
        Participant's termination of employment, termination of director
        status or termination of consultancy, but prior to the exercise of an
        Option, the Board of Directors determines that,


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        either prior or subsequent to the Participant's termination, the
        Participant engaged in conduct which would constitute "cause", then
        such Participant shall forthwith cease to have any right to exercise
        any Option.

    e.  A Participant to whom an Option has been granted under the Plan who
        is absent from work with the Company or with an Affiliate because of
        temporary disability (any disability other than a permanent and total
        Disability as defined in Paragraph 1 hereof), or who is on leave of
        absence for any purpose, shall not, during the period of any such
        absence, be deemed, by virtue of such absence alone, to have
        terminated such Participant's employment, director status or
        consultancy with the Company or with an Affiliate, except as the
        Administrator may otherwise expressly provide.

    f.  Options granted under the Plan shall not be affected by any change of
        employment or other service within or among the Company and any
        Affiliates, so long as the Participant continues to be an employee,
        director or consultant of the Company or any Affiliate, provided,
        however, if a Participant's employment by either the Company or an
        Affiliate should cease (other than to become an employee of an
        Affiliate or the Company), such termination shall affect the
        Participant's rights under any Option granted to such Participant in
        accordance with the terms of the Plan and the pertinent Option
        Agreement.

11. EFFECT OF TERMINATION OF SERVICE "FOR CAUSE".

     Except as otherwise provided in the pertinent Option Agreement, the
following rules apply if the Participant's service (whether as an employee,
director or consultant) with the Company or an Affiliate is terminated "for
cause" prior to the time that all of his or her outstanding Options have been
exercised:

    a.  All outstanding and unexercised Options as of the date the Participant
        is notified his or her service is terminated "for cause" will
        immediately be forfeited, unless the Option Agreement provides
        otherwise.

    b.  For purposes of this Article, "cause" shall include (and is not
        limited to) dishonesty with respect to the employer, insubordination,
        substantial malfeasance or non-feasance of duty, unauthorized
        disclosure of confidential information, and conduct substantially

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        prejudicial to the business of the Company or any Affiliate. The
        determination of the Administrator as to the existence of cause will
        be conclusive on the Participant and the Company.

    c.  "Cause" is not limited to events which have occurred prior to a
        Participant's termination of service, nor is it necessary that the
        Administrator's finding of "cause" occur prior to termination. If the
        Administrator determines, subsequent to a Participant's termination
        of service but prior to the exercise of an Option, that either prior
        or subsequent to the Participant's termination the Participant
        engaged in conduct which would constitute "cause", then the right to
        exercise any Option is forfeited.

    d.  Any definition is an agreement between the Participant and the
        Company or an Affiliate, which contains a conflicting definition of
        "cause" for termination and which is in affect at the time of such
        termination, shall supersede the definition in this Plan with respect
        to such Participant.

12. EFFECT OF TERMINATION OF SERVICE FOR DISABILITY.

     Except as otherwise provided in the pertinent Option Agreement, a
Participant who ceases to be an employee, director or consultant of the
Company or of an Affiliate by reason of Disability may exercise any Option
granted to such Participant:

    a.  To the extent that the right to purchase Shares has accrued on the
        date of his or her Disability; and

    b.  In the event rights to exercise the Option accrue periodically, to
        the extent of a pro rata portion of any additional rights as would
        have accrued had the Participant not become Disabled prior to the end
        of the accrual period which next ends following the date of
        Disability. The proration shall be based upon the number of days of
        such accrual period prior to the date of Disability.

     A Disabled Participant may exercise such rights only within a period of
not more than one (1) year after the date that the Participant became
Disabled, notwithstanding that the Participant might have been able to
exercise the Option as to some or all of the Shares on a later date if he or
she had not become disabled and had continued to be an employee, director or
consultant or, if earlier, within the originally prescribed term of the
Option.


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     The Administrator shall make the determination both of whether Disability
has occurred and the date of its occurrence (unless a procedure for such
determination is set forth in another agreement between the Company and such
Participant, in which case such procedure shall be used for such determination).
If requested, the Participant shall be examined by a physician selected or
approved by the Administrator, the cost of which examination shall be paid for
by the Company.

13. EFFECT OF DEATH WHILE AN EMPLOYEE, DIRECTOR OR CONSULTANT.

     Except as otherwise provided in the pertinent Option Agreement, in the
event of the death of a Participant to whom an Option has been granted while the
Participant is an employee, director or consultant of the Company or of an
Affiliate, such Option may be exercised by the Participant's Survivors:

     a.   To the extent exercisable but not exercised on the date of death; and

     b.   In the event rights to exercise the Option accrue periodically, to the
          extent of a pro rata portion of any additional rights which would have
          accrued had the Participant not died prior to the end of the accrual
          period which next ends following the date of death. The proration
          shall be based upon the number of days of such accrual period prior to
          the Participant's death.

     If the Participant's Survivors wish to exercise the Option, they must take
all necessary steps to exercise the Option within one (1) year after the date of
death of such Participant, notwithstanding that the decedent might have been
able to exercise the Option as to some or all of the Shares on a later date if
he or she had not died and had continued to be an employee, director or
consultant or, if earlier, within the originally prescribed term of the Option.

14. PURCHASE FOR INVESTMENT.

     Unless the offering and sale of the Shares to be issued upon the particular
exercise of an Option shall have been effectively registered under the
Securities Act of 1933, as now in force or hereafter amended (the "1933 Act"),
the Company shall be under no obligation to issue the Shares covered by such
exercise unless and until the following conditions have been fulfilled:

     a.   The person(s) who exercise such Option shall warrant to the Company,
          prior to receipt of the Shares that such person(s) are acquiring such
          Shares for their own


                                      -12-

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          respective accounts, for investment, and not with a view to, or for
          sale in connection with, the distribution of any such Shares, in which
          event the person(s) acquiring such Shares shall be bound by the
          provisions of the following legend which shall be endorsed upon the
          certificate(s) evidencing their Shares issued pursuant to such
          exercise or such grant:

               "The shares represented by this certificate have been taken for
               investment and they may not be sold or otherwise transferred by
               any person, including a pledgee, unless (1) either (a) a
               Registration Statement with respect to such shares shall be
               effective under the Securities Act of 1933, as amended, or (b)
               the Company shall have received an opinion of counsel
               satisfactory to it that an exemption from registration under such
               Act is then available, and (2) there shall have been compliance
               with all applicable state securities laws.

     b.   The Company shall have received an opinion of its counsel that the
          Shares may be issued upon such particular exercise in compliance with
          the 1933 Act without registration thereunder.

     The Company may delay issuance of the Shares until completion of any action
or obtaining of any consent which the Company deems necessary under any
applicable law (including, without limitation, state securities or "blue sky"
laws).

15. DISSOLUTION OR LIQUIDATION OF THE COMPANY.

     Upon the dissolution or liquidation of the Company, all Options granted
under this Plan which as of such date shall not have been exercised will
terminate and become null and void; provided, however, that if the rights of a
Participant or a Participant's Survivors have not otherwise terminated and
expired, the Participant or the Participant's Survivors will have the right
immediately prior to such dissolution or liquidation to exercise any Option to
the extent that the right to purchase Shares has accrued under the Plan as of
the date immediately prior to such dissolution or liquidation.

16. ADJUSTMENTS.

     Upon the occurrence of any of the following events, a Participant's rights
with respect to any Option granted to him or her hereunder which have not
previously been exercised in full


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shall be adjusted as hereinafter provided, unless otherwise specifically
provided in the written agreement bewteen the Participant and the Company
relating to such Option:

     A. STOCK DIVIDENDS AND STOCK SPLITS. If the shares of Common Stock shall
be subdivided or combined into a greater or smaller number of shares or if
the Company shall issue any shares of Common Stock as a stock dividend on its
outstanding Common Stock, the number of shares of Common Stock deliverable
upon the exercise of such Option shall be appropriately increased or
decreased proportionately, and appropriate adjustments shall be made in the
purchase price per share to reflect such subdivision, combination or stock
dividend.

     B. CONSOLIDATIONS OR MERGERS. If the Company is to be consolidated with
or acquired by another entity in a merger, sale of all or substantially all
of the Company's assets or otherwise (an "Acquisition"), the Administrator
or the board of directors of any entity assuming the obligations of the
Company hereunder (the "Successor Board"), shall, as to outstanding Options,
either (i) make appropriate provision for the continuation of such Options by
substituting on an equitable basis for the Shares then subject to such
Options either the consideration payable with respect to the outstanding
shares of Common Stock in connection with the Acquisition or securities of
any successor or acquiring entity; or (ii) upon written notice to the
Participants, provide that all Options must be exercised, to the extent then
exercisable, within a specified number of days of the date of such notice, at
the end of which period the Options shall terminate; or (iii) terminate all
Options in exchange for a cash payment equal to the excess of the Fair Market
Value of the shares subject to such Options (to the extent then exercisable)
over the exercise price thereof.

     C. RECAPITALIZATION OR REORGANIZATION. In the event of a
recapitalization or reorganization of the Company (other than a transaction
described in subparagraph B above) pursuant to which securities of the Company
or of another corporation are issued with respect to the outstanding shares
of Common Stock, a Participant upon exercising an option shall be entitled to
receive for the purchase price paid upon such exercise the securities he or
she would have received if he or she had exercised such Option prior to such
recapitalization or reorganization.

     D. MODIFICATION OF ISOS. Notwithstanding the foregoing, any adjustments
made pursuant to subparagraphs A, B or C with respect to ISOs shall be made
only after the Administrator, after consulting with counsel for the Company,
determines whether such adjustments would constitute a "modification" of such
ISOs (as that term is defined in Section 424(h) of the Code) or would


                             -14-

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cause any adverse tax consequences for the holders of such ISOs. If the
Administrator determines that such adjustments made with respect to ISOs
would constitute a modification of such ISOs, it may refrain from making such
adjustments, unless the holder of an ISO specifically requests in writing
that such adjustment be made and such writing indicates that the holder has
full knowledge of the consequences of such "modification" on his or her
income tax treatment with respect to the ISO.

17. ISSUANCES OF SECURITIES.

     Except as expressly provided herein, no issuance by the Company of shares
of stock of any class, or securities convertible into shares of stock of any
class, shall affect, and no adjustment by reason thereof shall be made with
respect to, the number or price of shares subject to Options. Except as
expressly provided herein, no adjustments shall be made for dividends paid in
cash or in property (including without limitation, securities) of the Company.

18. FRACTIONAL SHARES.

     No fractional share shall be issued under the Plan and the person
exercising such right shall receive from the Company cash in lieu of such
fractional share equal to the fair market value thereof determined in good
faith by the Board of Directors of the Company.

19. CONVERSION OF ISOs INTO NON-QUALIFIED OPTIONS; TERMINATION OF ISOs.

     The Administrator, at the written request of any Participant, may in
its discretion take such actions as may be necessary to convert such
Participant's ISOs (or any portions thereof) that have not been exercised on
the date of conversion into Non-Qualified Options at any time prior to the
expiration of such ISOs, regardless of whether the Participant is an employee
of the Company or an Affiliate at the time of such conversion. Such actions
may include, but not be limited to, extending the exercise period or reducing
the exercise price of the appropriate installments of such Options. At the
time of such conversion, the Administrator (with the consent of the
Participant) may impose such conditions on the exercise of the resulting
Non-Qualified Options as the Administrator in its discretion may determine,
provided that such conditions shall not be inconsistent with this Plan.
Nothing in the Plan shall be deemed to give any Participant the right to have
such Participant's ISO's converted into Non-Qualified Options, and no such
conversion shall occur until and unless the Administrator takes


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appropriate action. The Administrator, with the consent of the Participant,
may also terminate any portion of any ISO that has not been exercised at the
time of such termination.

20. WITHHOLDING.

     Upon the exercise of a Non-Qualified Option for less than the then Fair
Market Value or the making of a Disqualifying Disposition (as defined in
paragraph 21), the Company may withhold from the Participant's wages, if any,
or other remuneration, or may require the Participant to pay additional
federal, state, and local income tax withholding and employee contributions to
employment taxes in respect of the amount that is considered compensation
includible in such person's gross income. The Administrator in its discretion
may condition the exercise of an Option for less than the then Fair Market
Value on the Participant's payment of such additional income tax withholding
and employee contributions to employment taxes.

21. NOTICE TO COMPANY OF DISQUALIFYING DISPOSITION.

     Each Key Employee who receives an ISO must agree to notify the Company
in writing immediately after the Key Employee makes a Disqualifying
Disposition of any shares acquired pursuant to the exercise of an ISO. A
Disqualifying Disposition is any disposition (including any sale) of such
shares before the later of (a) two years after the date the Key Employee was
granted the ISO, or (b) one year after the date the Key Employee acquired
shares by exercising the ISO. If the Key Employee has died before such stock
is sold, these holding period requirements do not apply and no Disqualifying
Disposition can occur thereafter.

22. TERMINATION OF THE PLAN.

     The Plan will terminate on October 31, 2002, the date which is ten (10)
years from the EARLIER of the date of its adoption and the date of its
approval by the stockholders of the Company. The Plan may be terminated at an
earlier date by vote of the stockholders of the Company; provided, however,
that any such earlier termination will not affect any Options granted or
Option Agreements executed prior to the effective date of such termination.

23. AMENDMENT OF THE PLAN.

     The Plan may be amended by the stockholders of the Company. The Plan may
also be amended by the Administrator, including,


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without limitation, to the extent necessary to qualify any or all outstanding
Options granted under the Plan or Options to be granted under the Plan for
favorable federal income tax treatment (including deferral of taxation upon
exercise) as may be afforded incentive stock options under Section 422 of the
Code, to the extent necessary to ensure the qualification of the Plan under
Rule 16b-3, and to the extent necessary to qualify the shares issuable upon
exercise of any outstanding Options granted, or Options to be granted, under
the Plan for listing on any national securities exchange or quotation in any
national automated quotation system of securities dealers. Any amendment
approved by the Administrator which is of a scope that requires stockholder
approval in order to ensure favorable federal income tax treatment for any
incentive stock options or requires stockholder approval in order to ensure
the compliance of the Plan with Rule 16b-3 shall be subject to obtaining such
stockholder approval. Any modification or amendment of the Plan shall not,
without the consent of a Participant, affect his or her rights under an
Option previously granted to him or her. With the consent of the Participant
affected, the Administrator may amend outstanding Option Agreements in a manner
not inconsistent with the Plan.

24. EMPLOYMENT OR OTHER RELATIONSHIP.

     Nothing in this Plan or any Option Agreement shall be deemed to prevent
the Company or an Affiliate from terminating the employment, consultancy or
director status of a Participant, nor to prevent a Participant from
terminating his or her own employment, consultancy or director status or to
give any Participant a right to be retained in employment or other service by
the Company or any Affiliate for any period of time.

25. GOVERNING LAW.

     This Plan shall be construed and enforced in accordance with the law of
The Commonwealth of Massachusetts.


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