<PAGE>
 
                                                                    EXHIBIT 4(g)

          NEITHER THIS NOTE NOR THE SECURITIES INTO WHICH THIS NOTE IS
     CONVERTIBLE HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
     AMENDED (THE "SECURITIES ACT"), ANY STATE SECURITIES LAW OR ANY OTHER
     SECURITIES LAWS AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT
     PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OR
     PURSUANT TO AN AVAILABLE EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT
     TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND IN ACCORDANCE
     WITH APPLICABLE STATE SECURITIES LAWS.

No. CSN1999-X                                            U.S. $[            ]
                                                            March  30, 1999

                              ORGANOGENESIS INC.
                   FORM OF 7% CONVERTIBLE SUBORDINATED NOTE
                              DUE MARCH 29, 2004

     FOR VALUE RECEIVED, Organogenesis Inc. a corporation organized and existing
under the laws of the State of Delaware, having a principal place of business at
150 Dan Road, Canton, Massachusetts 02021 (the "COMPANY" ) promises to pay to
                                                -------                      
___________ , or its registered assigns (the "HOLDER" ), the principal sum of
Dollars ($_________), on March 29, 2004 or such earlier date that this Note is
required to be repaid as provided hereunder (the "MATURITY DATE") and to pay
                                                  -------------             
interest on the principal sum outstanding under this Note at the rate of 7% per
annum (or otherwise as described in Section 1.3) as described herein.

     Section 1.  Payment.
     ---------   ------- 

     1.1  Payment of Principal.   The Company shall pay all outstanding
          --------------------                                         
principal due on this Note on the Maturity Date or earlier as provided in
Section 5.2 herein.  Such payment on the Maturity Date shall be made in such
coin or currency of the United States of America as at the time of payment is
legal tender for payment of public and private debt.  Any earlier conversion of
the principal and interest thereon in accordance with the provisions of Section
5 shall be in the form of Common Stock on the principal balance so converted and
in the manner described in Section 1.3 as to the payment of accrued interest.

     1.2  Prepayment of Principal and Interest.    Except as set forth in
          ------------------------------------                           
Section 5 herein, this Note may not be prepaid in whole or in part at any time.

     1.3  Payment of Interest.   The Company shall pay all outstanding interest
          -------------------                                                  
due on this Note semi-annually or earlier as provided in Section 5.2 herein.
Interest will be payable on each of September 30 and March 31 (each an "INTEREST
PAYMENT DATE") of each year this Note is outstanding, except that the first
interest payment will be due on September 30, 1999.  Interest shall accrue from
the most recent date to which interest has been
<PAGE>
 
paid or, if no interest has been paid, from the date of original issuance and
shall continue until the following Interest Payment Date. Notwithstanding the
foregoing, upon receipt of a notice of conversion in accordance with the
provisions of Section 5 herein by either the Holder or the Company, interest
shall be payable in full within five (5) days following conversion of the Note
as to all accrued interest due on the principal sum outstanding under this Note
that has been converted into the Company's Common Stock through such conversion
date. Interest shall be calculated on the basis of a 360-day year and for the
actual number of days elapsed. Interest hereunder will be paid to the person in
whose name this Note is registered on the records of the Company regarding
registration and transfers of the Note (the "NOTE REGISTER"); provided, however,
                                             -------------    --------  ------- 
that the Company's obligation to a transferee of this Note arises only if such
transfer, sale or other disposition is made in accordance with the terms and
conditions hereof and of the Securities Purchase Agreement, dated as of March
30, 1999, as amended from time to time (the "PURCHASE AGREEMENT"), executed by
                                             ------------------
the original Holder. All sums hereunder shall bear interest at the rate of 10%
per annum from the Maturity Date through the date of payment or such earlier
date in which this Note is accelerated or converted through and including the
date of payment, or from the Interest Payment Date until the date of payment.
All of the foregoing payments of interest (other than payments subsequent to the
Maturity Date) shall be made in (a) such coin or currency of the United States
of America as at the time of payment is legal tender for payment of public and
private debt, (b) in Common Stock (as defined in Section 6), or (c) in any
combination of (a) and (b), at the Company's option. For purposes of clause (b),
the value of one share of Common Stock shall be, on the Interest Payment Date,
the Maturity Date or on the date of conversion of the Convertible Note pursuant
to Section 5 hereof, as applicable, an amount that is equal to the average of
the Per Share Market Value for one share of Common Stock for the twenty (20)
Trading Days immediately preceding such date. Notwithstanding the foregoing, the
Company is not permitted to pay any sums due hereunder in the Company's Common
Stock at any time when the Underlying Shares Registration Statement is not then
effective or shares of Common Stock are not listed for trading. Notwithstanding
anything to the contrary contained herein, the Company may not issue shares of
Common Stock in payment of the interest on principal if: (i) there is an
insufficient number of authorized shares of Common Stock reserved (pursuant to
Section 3.7 of the Purchase Agreement) for issue for full conversion of all of
the Notes issued pursuant to the Purchase Agreement; (ii) such shares are not
either registered for resale pursuant to the Registration Statement (as defined
in the Registration Rights Agreement) or freely transferable without volume
restrictions pursuant to Rule 144(k) promulgated under the Act, as determined by
counsel to the Company pursuant to a written opinion letter addressed and in
form and substance acceptable to the Holder and the transfer agent for such
shares, subject to receipt from the Holder of a representation from such Holder
that it is not an Affiliate of the Company; (iii) such shares are not listed or
quoted on the American Stock Exchange; or (iv) an Event of Default has occurred
and is continuing or an event that, with the passage of time or giving of notice
or both would constitute an Event of Default, has occurred and is continuing.

     Section 2.  Owner of Note.  Prior to due presentment to the Company for
     ---------   -------------                                              
transfer of this Note, the Company and any agent of the Company may treat the
person in whose name this Note is duly registered on the Note Register as the
owner hereof for the purpose of receiving payment as herein provided and for all
other purposes, whether or not this Note is overdue, and neither the Company nor
any such agent shall be affected by notice to the contrary.

                                       2
<PAGE>
 
     Section 3.  Subordination.
     ---------   ------------- 

     3.1  Note Subordinated to Senior Debt.  The payment of principal of,
          --------------------------------                               
interest on, and all other amounts payable with respect to, this Note
(collectively, the "SUBORDINATED PAYMENTS") are  hereby subordinated and junior
                    ---------------------                                      
in right of payment, to the extent and in the manner set forth herein to all
Senior Debt.  As used herein, the term "SENIOR DEBT" shall mean with respect to
                                        -----------                            
the Company (i) all indebtedness for money borrowed from any bank, trust
company, insurance company or other financial institution, including commercial
paper and accounts receivable sold or assigned by the Company to such
institutions, and (ii) all obligations of the Company as lessee under leases of
real or personal property; provided any such indebtedness in either event is not
                           --------                                             
convertible into Common Stock.  This Section 3 shall constitute a continuing
offer to all persons who, in reliance upon such provisions, become holders of,
or continue to hold, Senior Debt, whether now outstanding or hereafter created,
incurred, assumed or guaranteed, and such provisions are made for the benefit of
the holders of Senior Debt.  This Note is binding upon the Company and its
permitted successors and assigns and the Holder and its endorsees, each of whom,
by its acceptance of this Note, agrees to be bound by and comply with all of the
provisions of this Note.

     3.2  Payment Upon Dissolution, Etc.  Upon any payment or distribution of
          ------------------------------                                     
assets or securities of the Company of any kind or character, whether in cash,
property or securities, by way of set-off or otherwise of the Company (all such
payments and distributions being referred to collectively as "DISTRIBUTIONS"),
                                                              -------------   
upon any dissolution, winding up, liquidation (partial or complete) or
reorganization of the Company (whether voluntary or involuntary and whether in
bankruptcy, insolvency, receivership or other proceedings, or upon an assignment
for the benefit of creditors or any other marshalling of the assets and
liabilities of the Company or otherwise), each of the Company and the Holder, by
acceptance hereof, covenants and agrees that:

          (a) all Senior Debt shall first be paid in full, or provision made for
     such payment, in accordance with the terms of such Senior Debt and the
     documents evidencing such Senior Debt (hereinafter, "SENIOR DEBT
                                                          -----------
     DOCUMENTS") before any payment or distribution of any Distribution is made
     ---------
     on account of any Subordinated Payments and before the Holder shall be
     entitled to retain any amounts so paid or distributed in respect thereof;

          (b) any payments or distribution of any Distribution to which the
     Holder would be entitled except for the provisions of this Section, shall
     be paid or delivered by the Company or any debtor, custodian, receiver,
     trustee in bankruptcy, liquidating trustee, agent or other person making
     such payment or distribution, directly to the holders of Senior Debt or
     their representative or representatives or to the trustee or agent under
     any Senior Debt Document, as their respective interests may appear, to the
     extent necessary to pay in full all Senior Debt remaining unpaid in
     accordance with the terms of such Senior Debt and the Senior Debt
     Documents, after giving effect to any concurrent payment or distribution to
     or for the holders of such Senior Debt, before any payment or distribution
     is made to the Holder of this Note; and

                                       3
<PAGE>
 
          (c) in the event that, notwithstanding the foregoing, any payment or
     distribution of any Distribution shall be received by the Holder of this
     Note before all Senior Debt is paid in full, or provision made for the
     payment thereof, in accordance with the terms of such Senior Debt and the
     Senior Debt Documents, such payment or distribution shall be held in trust
     for the benefit of, and shall be paid over or delivered to, the holders of
     such Senior Debt or their representative or representatives, or to the
     trustee or agent under any Senior Debt Document, as their respective
     interests may appear, to the extent necessary to pay in full all Senior
     Debt remaining unpaid, after giving effect to any concurrent payment or
     distribution to the holders of such Senior Debt.

     The Company shall give prompt written notice to the holders of the
Convertible Notes of any dissolution, winding up, total liquidation or
reorganization of the Company within the meaning of this Section 3.2. Upon any
payment or distribution of assets of the Company referred to in this Section
3.2, the holders of the Convertible Notes shall be entitled to rely upon a
certificate of the trustee in bankruptcy, receiver, assignee for the benefit of
creditors or other liquidating agent making such payment or distribution,
delivered to the holders of the Notes, for the purpose of ascertaining the
persons entitled to participate in such distribution, the holders of the Senior
Indebtedness and other indebtedness of the Company, the amount thereof or
payable thereon, the amount or amounts paid or distributed thereon and all other
facts pertinent thereto or to this Section 3.2.

     3.3  No Payment Under Certain Circumstances.  No cash payment shall be made
          --------------------------------------                                
or agreed to be made, directly or indirectly, in cash, property or securities,
or by way of set-off or otherwise, by the Company of any Subordinated Payment
with respect to this Note if, at the time of such payment or immediately after
giving effect thereto, the Company shall be in default in the payment of any
principal of, premium, if any, or interest on, or any other amounts due with
respect to, any Senior Debt.

     3.4  No Impairment.  Nothing contained in this Note is intended to or shall
          -------------                                                         
impair, as between the Company, its creditors other than the holders of Senior
Debt and the Holder, the obligation of the Company, which is absolute and
unconditional, to pay to the Holder, subject to the rights of the holders of
Senior Debt, this Note, as and when the same shall become due and payable in
accordance with its terms (subject to the applicable requirements of the
Internal Revenue Code concerning withholding of taxes), or is intended to or
shall affect the relative rights of the holders and creditors of the Company
other than the holders of Senior Debt, nor shall anything herein or therein
prevent the Holder from exercising all remedies otherwise permitted by
applicable law or under the terms of this Note subject to the rights, if any,
under this Note, of the holders of Senior Debt in respect of Distributions
received upon the exercise of any such remedy.

     3.5  Subrogation.  Subject to the payment in full of all Senior Debt at the
          -----------                                                           
time outstanding, the Holder shall be subrogated (equally and ratably with the
holders of all indebtedness of the Company which, by its express terms, ranks on
a parity with this Note and is entitled to like rights of subrogation) to the
rights of the holders of Senior Debt (to the extent of

                                       4
<PAGE>
 
payments or distributions previously made to such holders of Senior Debt
pursuant to this Note) to receive payments or distributions of assets or
securities of the Company payable or distributable to holders of the Senior Debt
until all Subordinated Payments with respect to this Note shall be paid in full.
For purposes of such subrogation, no payments or distributions on the Senior
Debt shall, as between the Company, its creditors other than the holders of
Senior Debt, and the Holder, be deemed to be a payment of distribution by the
Company to or on account of the Senior Debt, and no payments or distributions to
the Holder of assets or securities by virtue of the subrogation herein provided
for shall, as between the Company, its creditors other than the holders of
Senior Debt, and the Holder, be deemed to be a payment to or on account of this
Note. The provisions of this Section are and are intended solely for the purpose
of defining the relative rights of the Holder, on the one hand, and the holders
of Senior Debt, on the other hand.

     3.6  No Impairment of Rights.  No right of any present or future holder of
          -----------------------                                              
any Senior Debt of the Company to enforce subordination as herein provided shall
at any time in any way be prejudiced or impaired by any act or failure to act on
the part of the Company or by any act or failure to act, in good faith, by any
such holder, or by any noncompliance by the Company with the terms, provisions
and covenants of this Note, regardless of any knowledge thereof with which any
such holder may have or be otherwise charged.

     3.7  Waiver of Notice.  The Holder, by its acceptance hereof, waives all
          ----------------                                                   
notice of the acceptance of the subordination provisions contained herein by
each holder of Senior Debt, whether no outstanding or hereafter incurred, and
waives reliance by each such holder upon such provisions.

     3.8  Subordination Rights Not Impaired by Acts/Omissions of the Company or
          ---------------------------------------------------------------------
Holders of Senior Debt.  The holders of Senior Debt may at any time or from time
----------------------                                                          
to time, and in their absolute discretion, change the manner, place or terms of
payment of, change or extend the time of payment of, renew or alter, any Senior
Debt, or amend or supplement any Senior Debt Document, or exercise or refrain
from exercising any other of their rights under the Senior Debt including
without limitation the waiver of default hereunder, all without notice to or
assent from the Holder.  No right of any present or future holders of any Senior
Debt to enforce subordination as provided herein shall at any time in any way be
prejudiced or impaired by any act or failure to act on the part of the Company
or by any act or failure to act by any such holder or by any noncompliance by
the Company with the terms of this Note, regardless of any knowledge thereof
which any such holder may have or be otherwise charged with.

     Section 4.  Default.
     ---------   ------- 

     4.1  Event of Default.  As used herein, the term "EVENT OF DEFAULT", means
          ----------------                             ----------------        
any one of the following events (whatever the reason and whether it shall be
voluntary or involuntary or effected by operation of law or pursuant to any
judgment, decree or order of any court, or any order, rule or regulation of any
Federal, state, local or foreign administrative or governmental body):

                                       5
<PAGE>
 
          (a) any default in the payment of the principal of, interest on or
     liquidated damages in respect of, this Note, as and when the same shall
     become due and payable on the Conversion Date, the Maturity Date, by
     acceleration or otherwise and which for payments of interest only shall
     continue for a period of three (3) days after the date such payment was
     due;

          (b) any representation or warranty of the Company shall prove to have
     been incorrect when given under, or the Company shall fail to observe or
     perform in any covenant or agreement under, or otherwise commit any breach
     of, this Note, the Purchase Agreement, the Warrant (as defined in the
     Purchase Agreement) or the Registration Rights Agreement (as defined in the
     Purchase Agreement), and such failure or breach shall not have been
     remedied within 30 days after the date on which notice of such failure or
     breach shall have been given;

          (c) the Company shall commence, or there shall be commenced against
     the Company a case under any applicable bankruptcy or insolvency laws as
     now or hereafter in effect or any successor thereto, or the Company
     commences any other proceeding under any reorganization, arrangement,
     adjustment of debt, relief of debtors, dissolution, insolvency or
     liquidation or similar law of any jurisdiction whether now or hereafter in
     effect relating to the Company or any Subsidiary thereof or there is
     commenced against the Company or any Subsidiary thereof any such
     bankruptcy, insolvency or other proceeding which remains undismissed for a
     period of 60 days; or the Company or any Subsidiary thereof is adjudicated
     insolvent or bankrupt; or any order of relief or other order approving any
     such case or proceeding is entered; or the Company or any Subsidiary
     thereof suffers any appointment of any custodian or the like for it or any
     substantial part of its property which continues undischarged or unstayed
     for a period of 60 days; or the Company or any Subsidiary thereof makes a
     general assignment for the benefit of creditors; or the Company shall fail
     to pay, or shall state that it is unable to pay, or shall be unable to pay,
     its debts generally as they become due; or the Company or any Subsidiary
     thereof shall call a meeting of its creditors with a view to arranging a
     composition or adjustment of its debts; or the Company or any Subsidiary
     thereof shall by any act or failure to act indicate its consent to,
     approval of or acquiescence in any of the foregoing; or any corporate or
     other action is taken by the Company or any Subsidiary thereof for the
     purpose of effecting any of the foregoing; or

          (d) the Common Stock shall be delisted from the American Stock
     Exchange or any other national securities exchange or market on which such
     Common Stock is listed for trading or suspended from trading thereon
     without being relisted or having such suspension lifted, as the case may
     be, within 30 Trading Days.

     4.2. Effect of Event of Default.  If during the time that any portion of
          --------------------------                                         
this Note remains outstanding, any Event of Default occurs and is continuing,
and in every such case, then the Holder may, by notice to the Company, declare
the full principal amount of this Note, together with all accrued but unpaid
interest hereon and other amounts owing hereunder to the date of acceleration,
to be immediately due and payable in cash without presentment, demand,

                                       6
<PAGE>
 
protest or other notice of any kind, all of which are waived by the Company,
notwithstanding anything herein contained to the contrary, and the Holder may
immediately and without expiration of any grace period enforce any and all of
its rights and remedies hereunder and all other remedies available to it under
applicable law. Such declaration may be rescinded and annulled by the Holder at
any time prior to payment hereunder. No such rescission or annulment shall
affect any subsequent Event of Default or impair any right consequent thereon.

     Section 5.  Conversion.
     ---------   ---------- 

     5.1  Conversion by Holder.  Subject to Section 5.11, at any time upon
          --------------------                                            
seventy-five (75) days' prior written notice to the Company at any time and from
time to time on or after March 30, 2000, (the "INITIAL CONVERSION DATE"), and
                                               -----------------------       
prior to the close of business on the Maturity Date or earlier as set forth in
this Section 5, the principal sums due under this Note shall be convertible into
shares of Common Stock at the Conversion Price, at the option of the Holder in
whole or in part.  The Company may waive the seventy-five (75) day notice
requirement at its sole discretion as to any Holder or Holders.  The Holder
shall effect conversions by surrendering this Note (or such portions thereof) to
be converted, together with the form of conversion notice attached hereto as
Exhibit A (the "HOLDER CONVERSION NOTICE") to the Company.  Each Holder
---------       ------------------------                               
Conversion Notice shall specify the principal amount of this Note to be
converted (which may not be less than $100,000 or such less principal amount of
this Note then held in the aggregate by such Holder) and the date on which such
conversion is to be effected (which, in any event, shall be no less than
seventy-five (75) days from the date of such notice under subparagraph (a)) (the
"HOLDER CONVERSION DATE", unless waived by the Company as set forth above).  If
 ----------------------                                                        
no Holder Conversion Date is specified in a Holder Conversion Notice, the Holder
Conversion Date shall be the date that is seventy-five (75) days after the date
that the Holder Conversion Notice is deemed delivered pursuant to Section 5.10.
Each Holder Conversion Notice, may be revoked and rescinded at the election of
the Holder exercised in its sole discretion prior to the Holder Conversion Date.
If the Holder is converting less than all of the principal amount represented by
this Note or if a conversion hereunder cannot be effected in full for any
reason, the Company shall honor such conversion to the extent permissible
hereunder and shall promptly deliver to such Holder (in the manner and within
the time set forth in Section 5.10) a new Note for such principal amount as has
not been converted.  Interest on the Note shall continue to accrue through the
Holder Conversion Date.

     5.2  Company Conversion.  At  the Company's option, at any time on or after
          ------------------                                                    
March 30, 2002, all but not less than all of the entire principal amount of this
Note may be prepaid by (a) conversion of such principal sums into shares of
Common Stock at the Conversion Price, (b) cash or (c) any combination of payment
in Common Stock at the Conversion Price and cash; provided, however, that the
                                                  --------  -------          
Company is not permitted to deliver a Company Conversion Notice (as defined
below) (a) at any time when the Underlying Shares Registration Statement is not
then effective or shares of Common Stock are not listed for trading, and (b) if
the average Per Share Market Value for the twenty (20) consecutive Trading Days
immediately preceding the date of issuance of the Company Conversion Notice does
not exceed the Conversion Price by at least one hundred sixty-seven percent
(167%) (e.g., $40.00 if the Conversion Price is $15.00; $38.67 if the Conversion
Price is $14.50).  The Company shall effect such conversion by delivering to the

                                       7
<PAGE>
 
Holder a written notice in the form attached hereto as Exhibit B (the "COMPANY
                                                       ---------       -------
CONVERSION NOTICE"), which Company Conversion Notice, once given, shall be
-----------------                                                         
irrevocable.  Each Company Conversion Notice shall specify the principal amount
together with accrued interest of this Note to be converted in accordance with
the provisions of Section 1.3 above.  The Company shall deliver such Company
Conversion Notice at least thirty (30) days before the date of conversion (such
date being hereinafter referred to as the "COMPANY CONVERSION DATE").  Upon its
                                           -----------------------             
receipt of a Company Conversion Notice, the Holder shall surrender the principal
amount of this Note subject to such notice at the office of the Company or of
any transfer agent for this Note or Common Stock.  If the Company is converting
less than the aggregate principal amount of this Note, the Company shall, upon
conversion of the principal amount of this Note subject to such Company
Conversion Notice and receipt of this Note surrendered for conversion, deliver
to the Holder, a replacement Note for such principal amount of this Note as has
not been converted.  Each of a Holder Conversion Notice and a Company Conversion
Notice is sometimes referred to herein as a "CONVERSION NOTICE," and each of a
                                             -----------------                
"Holder Conversion Date" and a "Company Conversion Date" is sometimes referred
to herein as a "CONVERSION DATE."
                ---------------  

     5.3  Delivery of Certificates.  Not later than five (5) Trading Days after
          ------------------------                                             
the Conversion Date, the Company will deliver to the Holder (i) a certificate or
certificates which shall be free of restrictive legends and trading restrictions
(other than any required by Section 3.1 of the Purchase Agreement) representing
the number of shares of the Common Stock being acquired upon the conversion of
the Note, (ii) a new Note in a principal amount equal to the principal amount of
the Note not converted; and (iii) a check in the amount of all accrued and
unpaid interest (if the Company has elected to pay accrued interest in cash),
together with all other amounts then due and payable in accordance with the
terms hereof, in respect of the portion of this Note tendered for conversion or,
if the Company has elected to pay accrued interest in shares of the Common
Stock, certificates, which shall be free of restrictive legends and trading
restrictions, representing such number of shares of the Common Stock as equals
such interest due as set forth in Section 1.3 herein; provided, however, that
                                                      --------  -------      
the Company shall not be obligated to issue certificates evidencing the shares
of Common Stock issuable upon conversion of the principal amount of this Note
until this Note is either delivered for conversion to the Company or any
transfer agent for this Note or the Common Stock, or the Holder notifies the
Company that such Note has been lost, stolen or destroyed and provides a bond
(or other adequate security) reasonably satisfactory to the Company to indemnify
the Company from any loss incurred by it in connection therewith (in which case
the Company shall issue a replacement Note in like principal amount).  The
Company shall, upon request of the Holder, use its best efforts to deliver any
certificate or certificates required to be delivered by the Company under this
Section electronically through the Depository Trust Corporation or another
established clearing corporation performing similar functions.  If in the case
of any Conversion Notice such certificate or certificates, including for
purposes hereof, any shares of the Common Stock to be issued on the Conversion
Date on account of accrued but unpaid interest hereunder, are not delivered to
or as directed by the applicable Holder by the fifth Trading Day after the
Conversion Date, the Holder shall be entitled by written notice to the Company
at any time on or before its receipt of such certificate or certificates
thereafter, to rescind such conversion, in which event the Company shall
immediately return the Note tendered for conversion.

                                       8
<PAGE>
 
     If the Company shall fail to issue to a Holder on a timely basis as
described in this Section 5.3 the number of shares of Common Stock to which such
Holder is entitled upon such Holder's conversion of this Convertible Note, the
Company shall pay damages to such Holder equal to the greater of (A) actual
damages incurred by such holder as a result of such Holder's having needed to
"buy in" shares of Common Stock to satisfy its securities delivery requirements
("BUY IN ACTUAL DAMAGES") and (B) after the effective date of the Registration
Statement, if the Company fails to deliver such certificates within three (3)
days after the last possible date which the Company could have issued such
Common Stock to such Holder without violating this Section 5.3, on each date
such conversion is not timely effected, an amount equal to one percent (1%) of
the product of (A) the number of shares of Common Stock not issued to the Holder
on a timely basis and to which such holder is entitled and (B) the Closing Bid
Price of the Common Stock on the last possible date on which the Company could
have issued such Common Stock to such holder with out violating this Section
5.3.

     5.4  Conversion Price.  The "CONVERSION PRICE" shall be $14.50 provided
          ----------------        ----------------                  --------
that, (a) if the registration statement registering the resale of shares of
Common Stock issuable upon conversion of this Note and payment of interest
thereunder and naming the Holder as a Selling Stockholder thereunder in
accordance with the Registration Rights Agreement of even date herewith (the
"UNDERLYING SHARES REGISTRATION STATEMENT") is not filed on or prior to the 45th
 ----------------------------------------                                       
day after the Original Issue Date, or (b) the Company fails to file with the
Securities and Exchange Commission (the "COMMISSION") a request for acceleration
                                         ----------                             
in accordance with Rule 12d1-2 promulgated under the Securities Exchange Act of
1934, as amended, within five (5) days of the date that the Company is notified
(orally or in writing, whichever is earlier) by the Commission that an
Underlying Shares Registration Statement will not be "reviewed" or is not
subject to further review or comment by the Commission, or (c) if the Underlying
Shares Registration Statement is not declared effective by the Commission on or
prior to the 90th day after the Original Issue Date, or (d) if such Underlying
Shares Registration Statement is filed with and declared effective by the
Commission but thereafter ceases to be effective as to all Registrable
Securities (as such term is defined in the Registration Rights Agreement) at any
time prior to the expiration of the "Effectiveness Period" (as such term as
defined in the Registration Rights Agreement), without being succeeded by a
subsequent Underlying Shares Registration Statement filed with and declared
effective by the Commission within 10 Business Days (as defined in Section 6),
or (e) if trading in the Common Stock shall be suspended for any reason for more
than five Trading Days, or (f) if the conversion rights of the Holder of this
Note hereunder are suspended for any reason (any such failure being referred to
as an "EVENT," and for purposes of clauses (a), (c) and (f) the date on which
       -----                                                                 
such Event occurs, or for purposes of clause (b) the date on which such five (5)
days period is exceeded, or for purposes of clause (d) the date which such ten
(10) Business Day-period is exceeded, or for purposes of clause (e) the date on
which such five (5) Trading Day period is exceeded, being referred to as "EVENT
                                                                          -----
DATE"), the Conversion Price shall be decreased by 1% on the Event Date and each
----                                                                            
monthly anniversary thereof until such time as the applicable Event is cured
(i.e., the Conversion Price would decrease by 1% as of the Event Date and 2% as
of the one month anniversary of such Event Date).  Any decrease in the
Conversion Price pursuant to this Section shall remain in effect notwithstanding
the fact that the Event causing such decrease has been subsequently cured and
further monthly decreases have ceased.  The provisions of this Section are not
exclusive and shall in no way limit

                                       9
<PAGE>
 
the Company's obligations under the Registration Rights Agreement. Any time
period set forth in clauses (a) through (c) of this Section 5.4 shall be
extended for such period of time as allowed under the penultimate paragraph of
Section 3 of the Registration Rights Agreement.

     5.5  Adjustments to Conversion Price.  The Conversion Price and number of
          -------------------------------                                     
shares of Common Stock issuable upon conversion of this Note are subject to
adjustment from time to time as set forth in this Section 5.5.  Upon each such
adjustment of the Conversion Price pursuant to this Section 5.5, the Holder
shall thereafter be entitled to convert this Note, at the Conversion Price
resulting from such adjustment, the number of shares of Common Stock obtained by
multiplying the Conversion Price in effect immediately prior to such adjustment
by the number of shares of Common Stock issuable upon conversion of this Note
immediately prior to such adjustment and dividing the product thereof by the
Conversion Price resulting from such adjustment.

          (a) If the Company shall at any time while this Note is outstanding
     (i) pay a stock dividend or otherwise make a distribution or distributions
     on shares of its Common Stock or any other equity or equity equivalent
     securities payable in shares of the Common Stock, (ii) subdivide
     outstanding shares of the Common Stock into a larger number of shares, or
     (iii) combine outstanding shares of the Common Stock into a smaller number
     of shares, the Conversion Price then in effect shall be multiplied by a
     fraction of which the numerator shall be the number of shares of the Common
     Stock (excluding treasury shares, if any) outstanding before such event and
     of which the denominator shall be the number of shares of the Common Stock
     (excluding treasury shares, if any) outstanding after such event.  Any
     adjustment made pursuant to this Section 5.5(a) shall become effective
     immediately after the record date for the determination of stockholders
     entitled to receive such dividend or distribution and shall become
     effective immediately after the effective date in the case of a
     subdivision, combination or reclassification.

          (b) If the Company shall at any time while this Note is outstanding,
     issue rights or warrants to all holders of the Common Stock (and not to the
     Holder of this Note) entitling them to subscribe for or purchase shares of
     the Common Stock at a price per share less than the Per Share Market Value
     of the Common Stock at the record date mentioned below, the Conversion
     Price then in effect shall be multiplied by a fraction, of which the
     denominator shall be the number of shares of the Common Stock (excluding
     treasury shares, if any) outstanding on the date of issuance of such rights
     or warrants plus the number of additional shares of the Common Stock
     offered for subscription or purchase, and of which the numerator shall be
     the number of shares of the Common Stock (excluding treasury shares, if
     any) outstanding on the date of issuance of such rights or warrants plus
     the number of shares which the aggregate offering price of the total number
     of shares so offered would purchase at such Per Share Market Value.  Such
     adjustment shall be made whenever such rights or warrants are issued, and
     shall become effective immediately after the record date for the
     determination of stockholders entitled to receive such rights or warrants.
     However, upon the expiration of any right or warrant to purchase shares of
     the Common Stock the issuance of which resulted in an adjustment

                                       10
<PAGE>
 
     in the Conversion Price pursuant to this Section 5.5(b), if any such right
     or warrant shall expire and shall not have been exercised, the Conversion
     Price shall immediately upon such expiration be recomputed and effective
     immediately upon such expiration be increased to the price which it would
     have been (but reflecting any other adjustments in the Conversion Price
     made pursuant to the provisions of this Section 5.5 after the issuance of
     such rights or warrants) had the adjustment of the Conversion Price made
     upon the issuance of such rights or warrants been made on the basis of
     offering for subscription or purchase only that number of shares of the
     Common Stock actually purchased upon the exercise of such rights or
     warrants actually exercised.

          (c) If the Company shall at any time while this Note is outstanding,
     distribute to all holders of the Common Stock (and not to the Holder of
     this Note) evidences of its indebtedness or assets or rights or warrants to
     subscribe for or purchase any Company security (excluding those referred to
     in Sections 5.5 (a) and (b) above), then in each such case the Conversion
     Price at which the Note shall thereafter be convertible shall be determined
     by multiplying the Conversion Price in effect immediately prior to the
     record date fixed for determination of stockholders entitled to receive
     such distribution by a fraction of which the denominator shall be the Per
     Share Market Value of the Common Stock determined as of the record date
     mentioned above, and of which the numerator shall be such Per Share Market
     Value of the Common Stock on such record date less the then fair market
     value at such record date of the portion of such assets or evidence of
     indebtedness so distributed as determined by the Board of Directors in good
     faith applicable to one outstanding share of the Common Stock.  Such
     adjustment shall be made whenever any such distribution is made and shall
     become effective immediately after the record date mentioned above.

          (d) All calculations under this Section 5.5 shall be made to the
     nearest cent or the nearest 1/100th of a share, as the case may be.

          (e) Whenever the Conversion Price is adjusted pursuant to Section 5.5
     (a),(b) or (c), the Company shall promptly mail to the Holder of this Note
     in accordance with Section 5.10, a notice setting forth the Conversion
     Price after such adjustment and setting forth a brief statement of the
     facts requiring such adjustment.

          (f) In case of any reclassification or change of the shares of Common
     Stock issuable upon exercise of this Warrant (other than a change in par
     value, or as a result of a subdivision or combination (covered by (a)
     above), but including any change in the shares into one or more classes or
     series of shares), or in case of any consolidation or merger of another
     corporation into the Company in which the Company is the continuing
     corporation and in which there is a reclassification or change (including a
     change to the right to receive shares of stock (other than Common Stock),
     other securities, property or cash) of the shares of Common Stock (other
     than a change in par value, or as a result of a subdivision or combination,
     but including any change in the shares into one or more classes or series
     of shares), then the Holder shall have the right thereafter to convert this
     Note only into the shares of stock and other securities of the Company and
     property

                                       11
<PAGE>
 
     receivable or deemed to be held by holders of Common Stock following such
     reclassification, change, consolidation or merger, and the Holder shall
     thereafter upon conversion of this Note be entitled to receive such amount
     of securities or property attributable to the number of shares of Common
     Stock such Holder would have been entitled to receive had such Holder
     converted this Note immediately prior to such action. The terms of any such
     reclassification or other action shall include such terms so as to continue
     to give to the Holder the right to receive the securities or property set
     forth in this Section 5.5(f) upon any exercise following such
     reclassification or other action.

          (g) In case of any consolidation of the Company with, or merger of the
     Company with or into, another corporation (other than a merger or
     consolidation in which the Company is the surviving or continuing
     corporation), or in case of any sale, lease or conveyance to another
     corporation of the property and assets of any nature of the Company as an
     entirety or substantially as an entirety, such successor, leasing or
     purchasing corporation, as the case may be, shall (i) execute an agreement,
     signed by the successor, leasing or purchasing corporation and the Holder,
     providing that the Holder shall have the right thereafter to receive upon
     conversion of this Note, solely the kind and amount of shares of stock and
     other securities, property, cash or any combination thereof receivable upon
     such consolidation, merger, sale, lease or conveyance by a holder of the
     number of shares of Common Stock for which this Note might have been
     converted immediately prior to such consolidation, merger, sale, lease or
     conveyance, and (ii) make effective provision in its certificate of
     incorporation or otherwise, if necessary, to effect such agreement.  Such
     agreement shall provide for adjustments which shall be as nearly equivalent
     as practicable to the adjustments in this Section 5.5.

          (h)  If:

               A.   the Company shall declare a dividend (or any other
                    distribution) on its Common Stock; or

               B.   the Company shall declare a special nonrecurring cash
                    dividend on or a redemption (other than redemptions of the
                    stock of employees upon their termination of employment with
                    the Company) of its Common Stock or

               C.   the Company shall authorize the granting to all holders of
                    the Common Stock rights or warrants to subscribe for or
                    purchase any shares of capital stock of any class or of any
                    rights; or

               D.   the approval of any stockholders of the Company shall be
                    required in connection with any reclassification of the
                    Common Stock of the Company, any consolidation or merger to
                    which the Company is a party, any sale or transfer of all or
                    substantially all of the assets of the Company, of any
                    compulsory share of exchange whereby

                                       12
<PAGE>
 
                    the Common Stock is converted into other securities, cash or
                    property; or

               E.   the Company shall authorize the voluntary or involuntary
                    dissolution, liquidation or winding up of the affairs of the
                    Company;

then the Company shall cause to be filed at each office or agency maintained for
the purpose of conversion of this Note, and shall cause to be mailed to the
Holder of this Note at its last address as it shall appear upon the stock books
of the Company, no later than forty-five (45) calendar days prior to the
applicable record or effective date hereinafter specified, a notice stating (x)
the date on which a record is to be taken for the purpose of such dividend,
distribution, redemption, rights or warrants, or if a record is not to be taken,
the date as of which the holders of the Common Stock of record to be entitled to
such dividend, distributions, redemption, rights or warrants are to be
determined or (y) the date on which such reclassification, consolidation,
merger, sale, transfer or share exchange is expected to become effective or
close, and the date as of which it is expected that holders of the Common Stock
of record shall be entitled to exchange their shares of Common Stock for
securities, cash or other property deliverable upon such reclassification,
consolidation, merger, sale, transfer or share exchange; provided, however, that
                                                         --------  -------      
the failure to mail such notice or any defect therein or in the mailing thereof
shall not affect the validity of the corporate action required to be specified
in such notice.  The Holder is entitled to convert this Note during the period
commencing the date of such notice to the effective date of the event triggering
such notice.

     5.6  Conditions Adversely Affecting Holder.  If at any time conditions
          -------------------------------------                            
shall arise by reason of action taken by the Company which in the good faith
opinion of the Board of Directors are not adequately covered by the other
provisions hereof and which might adversely affect the rights of the Holder
(different than or distinguished from the effect generally on rights of holders
of any class of the Company's capital stock) or if at any time any such
conditions are expected to arise by reason of any action contemplated by the
Company, the Company shall mail a written notice briefly describing the action
contemplated and the adverse effects of such action on the rights of the Holder
at least thirty (30) calendar days prior to the effective date of such action,
and an appraiser mutually acceptable to the Holder and the Company shall give
its opinion as to the adjustment, if any (not inconsistent with the standards
established in this Section 5), of the Conversion Price (including, if
necessary, any adjustment as to the securities into which this Note may
thereafter be convertible) and any distribution which is or would be required to
preserve without diluting the rights of the Holder.  The determination of the
appraiser shall be final.

     5.7  Reservation of Common Stock.  The Company covenants that it will at
          ---------------------------                                        
all times reserve and keep available out of its authorized and unissued shares
of Common Stock solely for the purpose of issuance upon conversion of this Note
and payment of interest on this Note, each as herein provided, free from
preemptive rights or any other actual contingent purchase rights of persons
other than the Holder, such number of shares of Common Stock as shall be from
time to time sufficient to effect the conversion of this Note (taking into
account the adjustments and

                                       13
<PAGE>
 
restrictions of Section 5.5) and payment of interest hereunder in Common Stock
in accordance with the terms hereof and of the Purchase Agreement. The Company
covenants that all shares of the Common Stock that shall be so issuable shall,
upon issue, be duly and validly authorized, issued and fully paid, nonassessable
and, if the Underlying Shares Registration Statement has been declared effective
under the Securities Act, all such registered shares shall be freely tradeable.

     5.8  No Fractional Shares.  Upon a conversion hereunder the Company shall
          --------------------                                                
not be required to issue stock certificates representing fractions of shares of
Common Stock, but may if otherwise permitted, make a cash payment in respect of
any final fraction of a share based on the Conversion Price at such time.  If
the Company elects not, or is unable, to make such a cash payment, the holder
shall be entitled to receive, in lieu of the final fraction of a share, one
whole share of Common Stock.

     5.9  Payment of Transfer Taxes, Etc.  The issuance of certificates for
          -------------------------------                                  
shares of the Common Stock on conversion of this Note shall be made without
charge to the Holder hereof for any documentary stamp or similar taxes that may
be payable in respect of the issue or delivery of such certificate, provided
that the Company shall not be required to pay any tax that may be payable in
respect of any transfer involved in the issuance and delivery of any such
certificate upon conversion in a name other than that of the Holder of this Note
so converted and the Company shall not be required to issue or deliver such
certificates unless or until the person or persons requesting the issuance
thereof shall have paid to the Company the amount of such tax or shall have
established to the satisfaction of the Company that such tax has been paid.

     5.10 Notices.  Any and all notices or other communications or deliveries to
          -------                                                               
be provided by the Holder of this Note hereunder, including, without limitation,
any Holder Conversion Notice, shall be in writing and delivered personally, by
facsimile, sent by a nationally recognized overnight courier service or sent by
certified or registered mail, postage prepaid, addressed to the Company, at 150
Dan Road, Canton, MA 02021 (facsimile number (781) 575-1570, Attention: Herbert
M. Stein, Chairman and Chief Executive Officer and Donna L. Abelli, Chief
Financial Officer, with copy to Mintz, Levin, Cohn, Ferris, Glovsky and Popeo,
P.C., One Financial Center, Boston, Massachusetts 02111 Attention: Neil H.
Aronson, Esquire and John J. Cheney, Esquire (facsimile number (617) 542-2241),
or such other address or facsimile number as the Company may specify for such
purposes by notice to the Holder delivered in accordance with this Section.  Any
and all notices or other communications or deliveries to be provided by the
Company hereunder shall be in writing and delivered personally, by facsimile,
sent by a nationally recognized overnight courier service or sent by certified
or registered mail, postage prepaid, addressed to the Holder of this Note at the
facsimile telephone number or address of such Holder appearing on the books of
the Company, or if no such facsimile telephone number or address appears, at the
principal place of business of the holder with a copy to Kramer Levin Naftalis &
Frankel LLP, 919 Third Avenue, New York, New York 10022, Attention:  Ezra G.
Levin, Esquire  (facsimile no.: (212) 715-8000).  Any notice or other
communication or deliveries hereunder shall be deemed given and effective on the
earliest of (i) the date of transmission, if such notice or communication is
delivered via facsimile at the facsimile telephone number specified in this
Section prior to 4:30 p.m. (Eastern Standard time),

                                       14
<PAGE>
 
(ii) the date after the date of transmission, if such notice or communication is
delivered via facsimile at the facsimile telephone number specified in this
Section later than 4:30 p.m. (Eastern Standard time) on any date and earlier
than 11:59 p.m. (Eastern Standard time)on such date, (iii) four days after
deposit in the United States mails, (iv) the Business Day following the date of
mailing, if send by nationally recognized overnight courier service, or (v) upon
actual receipt by the party to whom such notice is required to be given.

     5.11  Other Actions.  Notwithstanding anything in this Article V to the
           -------------                                                    
contrary, in the event of the occurrence of any of the following: (i) any
Persons is or becomes the "beneficial owner" as defined in Rules 13d-3 and 13d-5
under the Securities Exchange Act of 1934, as amended, directly or indirectly,
of more than 35% of the Common Stock or (ii) individuals who at the date hereof
constituted the Board of Directors (together with any such individuals whose
election by the Board of Directors or whose nomination for election by the
stockholders of the Company was approved by a majority of the directors then
still in office who were directors on the date hereof or persons whose election
as directors or nomination for election was previously so approved) cease for
any reason to constitute a majority of the Board of Directors then in office,
(iii) a tender or exchange offer made to the stockholders of the Company, (iv)
the Company delivers a Company Conversion Notice of its intent to prepay this
Note in cash or in any combination of cash and Common Stock, or (v) the Company
enters into an agreement for the consolidation of the Company with, or merger of
the Company with or into, another corporation, or the sale, lease or conveyance
to another corporation of the property and assets of any nature of the Company
as an entirety or substantially as an entirety, the Holder shall be entitled to
convert this Note in whole or in part into shares of Common Stock immediately
upon prior written notice to the Company. The Holder shall effect conversion by
surrendering this Note (or such portions thereof) to be converted together with
a Conversion Notice, which shall specify the principal amount of this Note to be
converted and the Holder Conversion Date (which shall be no less than five (5)
days from the date of such notice).

     Section 6.  Definitions.  For the purposes hereof, the following terms
     ---------   -----------                                               
shall have the following meanings:

          "BUSINESS DAY" means any day except Saturday, Sunday and any day which
           ------------                                                         
shall be a legal holiday or a day on which banking institutions in Boston are
authorized or required by law or other government action to close.

          "COMMON STOCK" means the common stock, $.01 par value per share, of
           ------------                                                      
the Company and stock of any other class into which such shares may hereafter
have been reclassified or changed.

          "ORIGINAL ISSUE DATE" shall mean the date of the first issuance of
           -------------------                                              
this Note regardless of the number of transfers of this Note and regardless of
the number of instruments which may be issued to evidence this Note.

          "PER SHARE MARKET VALUE" means on any particular date (a) the closing
           ----------------------                                              
price per share of the Common Stock on such date on the American Stock Exchange
or other stock

                                       15
<PAGE>
 
exchange or quotation system on which the Common Stock is then listed or if
there is no such price on such date, then the closing price on such exchange or
quotation system on the date nearest preceding such date, or (b) if the Common
Stock is not listed then on the American Stock Exchange or any stock exchange or
quotation system, the closing price for a share of Common Stock in the OTC
Bulletin Board or the over-the-counter market, as reported by the National
Quotation Bureau Incorporated or similar organization or agency succeeding to
its functions of reporting prices) at the close of business on such date, or (c)
if the Common Stock is not then reported by the National Quotation Bureau
Incorporated (or similar organization or agency succeeding to its functions of
reporting prices), then the average of the "Pink Sheet" quotes for the relevant
conversion period, as determined in good faith by the Holder, or (d) if the
Common Stock is not then publicly traded, the fair market value of a share of
Common Stock as determined by a nationally recognized or major regional
investment banking firm or firm of independent certified public accountants of
recognized standing (which may be the firm that regularly examines the financial
statements of the Company) (an "APPRAISER") mutually selected in good faith by
                                ---------
the Holders of a majority in interest of the Notes and the Company. Any
determination made by the Appraiser shall be final and binding upon the Company
and the Holder.

          "PERSON" means a corporation, an association, a partnership,
           ------                                                     
organization, a business, an individual, a government or political subdivision
thereof or a governmental agency.

          "TRADING DAY" means (a) a day on which the Common Stock is traded on
           -----------                                                        
the American Stock Exchange or other stock exchange or market on which the
Common Stock has been listed, or (b) if the Common Stock is not listed on the
American Stock Exchange or any stock exchange or market, a day on which the
Common Stock is traded in the over-the-counter market, as reported by the OTC
Bulletin Board, or (c) if the Common Stock is not quoted on the OTC Bulletin
Board, a day on which the Common Stock is quoted in the over-the-counter market
as reported by the National Quotation Bureau Incorporated (or any similar
organization or agency succeeding its functions of reporting prices).

          "UNDERLYING SHARES" means the number of shares of Common Stock into
           -----------------                                                 
which this Note is convertible in accordance with the terms hereof and the
Purchase Agreement.

     Section 7.  No Impairment.  Except as expressly provided in Section 3 or as
     ---------   -------------                                                  
elsewhere provided herein, no provision of this Note shall alter or impair the
obligation of the Company, which is absolute and unconditional, to pay the
principal of, and interest on, this Note at the time, place, and rate, and in
the securities, coin and currency, herein prescribed.

     Section 8.  No Right As Stockholder.  This Note shall not entitle the
     ---------   -----------------------                                  
Holder to any of the rights of a stockholder of the Company, including without
limitation, the right to vote, to receive dividends and other distributions, or
to receive any notice of, or to attend, meetings of stockholders or any other
proceedings of the Company, unless and to the extent converted into shares of
Common Stock in accordance with the terms hereof.

                                       16
<PAGE>
 
     Section 9.   Lost Note.  If this Note shall be mutilated, lost, stolen or
     ---------    ---------                                                   
destroyed, the Company shall execute and deliver, in exchange and substitution
for and upon cancellation of a mutilated Note, or in lieu of or in substitution
for a lost, stolen or destroyed Note, a new Note for the principal amount of
this Note so mutilated, lost, stolen or destroyed but only upon receipt of
evidence of such loss, theft or destruction of such Note, and of the ownership
hereof, and indemnity, if requested, all reasonably satisfactory to the Company.

     Section 10.  Governing Law.  This Note shall be governed by and construed
     ----------   -------------                                               
in accordance with the laws of the Commonwealth of Massachusetts, without giving
effect to conflicts of laws thereof.

     Section 11.  Waivers.  Any waiver by the Company or the Holder of a breach
     ----------   -------                                                      
of any provision of this Note shall not operate as or be construed to be a
waiver of any other breach of such provision or of  any breach of any other
provision of this Note.  The failure of the Company or the Holder to insist upon
strict adherence to any term of this Note on one or more occasions shall not be
considered a waiver or deprive that party of the right thereafter to insist upon
strict adherence to that term or any other term of this Note.  Any waiver must
be in writing.

     Section 12.  Invalidity.  If any provision of this Note is invalid, illegal
     ----------   ----------                                                    
or unenforceable, the balance of this Note shall remain in effect, and if any
provision is inapplicable to any person or circumstance, it shall nevertheless
remain applicable to all other persons and circumstances.
 
     Section 13.  Business Day.  Whenever any payment or other obligation
     ----------   ------------                                           
hereunder shall be due on a day other than a Business Day, such payment shall be
made on the next succeeding Business Day (or, if such next succeeding Business
Day falls in the next calendar month, the preceding Business Day in the
appropriate calendar month).

     IN WITNESS WHEREOF, the Company has caused this instrument to be duly
executed by an officer thereunto duly authorized as of the date first above
indicated.

                                    ORGANOGENESIS  INC.
 

                                    By:___________________________________
                                       Herbert M. Stein, Chairman and
                                       Chief Executive Officer
Attest:



By:_____________________________
   Name:
   Title:

                                       17
<PAGE>
 
                                   EXHIBIT A

                             NOTICE OF CONVERSION

(To be Executed by the Registered Holder
in order to Convert the Note)

The undersigned hereby elects to convert Note No. [  ] into shares of Common
Stock, $.01 par value per share (the "Common Stock"), of ORGANOGENESIS INC. (the
"Company") according to the conditions hereof, as of the date written below.  If
shares are to be issued in the name of a person other than undersigned, the
undersigned will pay all transfer taxes payable with respect thereto and is
delivering herewith such certificates and opinions as reasonably requested by
the Company in accordance therewith.  No fee will be charged to the holder for
any conversion, except for such transfer taxes, if any.

Conversion calculations:
                        _______________________________________________________ 
                        Date to Effect Conversion

                        _______________________________________________________ 
                        Principal Amount of Note to be Converted

                        _______________________________________________________ 
                        Remaining Principal Balance Following Note Conversion

                        _______________________________________________________ 
                        Number of shares of Common Stock to be Issued

                        _______________________________________________________ 
                        Applicable Conversion Price

                        _______________________________________________________ 
                        Signature

                        _______________________________________________________ 
                        Name

                        _______________________________________________________ 
                        Address

The Company undertakes to promptly upon its receipt of this conversion notice
(and, in any case prior to the time it effects the conversion requested hereby),
notify the converting holder by facsimile of the number of shares of Common
Stock outstanding on such date and the number of shares of Common Stock which
would be issuable to the holder if the conversion requested in this conversion
notice were effected in full.

                                       18
<PAGE>
 
                                   EXHIBIT B
                                        
                               ORGANOGENESIS INC.
                                        
                              NOTICE OF CONVERSION
                         AT THE ELECTION OF THE COMPANY
                                        

The undersigned in the name and on behalf of ORGANOGENESIS INC. (the "Company")
hereby notifies the addressee hereof that the Company hereby elects to exercise
its right to convert the above Note No. [   ] into shares of Common Stock, $.01
par value per share (the  Common Stock ), of the Company according to the
conditions hereof, as of the date written below.  No fee will be charged to the
Holder for any conversion hereunder, except for such transfer taxes, if any,
which may be incurred by the Company if shares are to be issued in the name of a
person other than the person to whom this notice is addressed.

Conversion calculations:
                        _______________________________________________________ 
                        Date to Effect Conversion

                        _______________________________________________________ 
                        Principal Amount of Note to be Converted

                        _______________________________________________________ 
                        Number of shares of Common Stock to be Issued

                        _______________________________________________________ 
                        Applicable Conversion Price

                        _______________________________________________________ 
                        Signature

                        _______________________________________________________ 
                        Name:

                        _______________________________________________________ 
                        Address:

                                       19