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                                                                    EXHIBIT 10.9

1. Adopted by the Board of Directors on May 1, 1993; Approved by the
   stockholders on June 25, 1993.

2. Amended by the Board of Directors on February 7, 1995; Approved by the
   stockholders on May 19, 1995.

3. Amended by the Board of Directors on March 3, 1997; [Approved by the
   stockholders on May 28, 1997].

                        GENZYME TRANSGENICS CORPORATION

                       1993 Employee Stock Purchase Plan
    l. Purpose.

    The purpose of this 1993 Employee Stock Purchase Plan (the "Plan") is to
provide employees of Genzyme Transgenics Corporation (the "Company"), and its
subsidiaries, who wish to become shareholders of the Company an opportunity to
purchase Common Stock of the Company (the "Shares"). The Plan is intended to
qualify as an "employee stock purchase plan" within the meaning of Section 423
of the Internal Revenue Code of 1986, as amended (the "Code").

    2. Eligible Employees.

    Subject to the provisions of Sections 7, 8 and 9 below, any individual who
is a full-time employee (as defined below) of the Company, or any of its
subsidiaries (as defined in Section 424(f) of the Code) the employees of which
are designated by the Board of Directors as eligible to participate in the Plan,
is eligible to participate in any Offering of Shares (as defined in Section 3
below) made by the Company hereunder. Full-time employees shall include all
employees whose customary employment is:

          (a) 20 hours or more per week and
          (b) more than five months

in the calendar year during which said Offering Date occurs or in the
calendar year immediately preceding such year.

    3. Offering Dates.

    From time to time, the Company, by action of the Board of Directors, will
grant rights to purchase Shares to employees eligible to participate in the Plan
pursuant to one or more offerings (each of which is an "Offering" on a date or
series of dates (each of which is an "Offering Date") designated for this
purpose by the Board of Directors.

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    4. Prices.

    The price per share for each grant of rights hereunder shall be the lesser
of:

          (a) eighty-five percent (85%) of the fair market value of a Share
              on the Offering Date on which such right was granted; or
          (b) eighty-five percent (85%) of the fair market value of a Share
              on the date such right is exercised.

At its discretion, the Board of Directors may determine a higher price for a
grant of rights.

    5. Exercise of Rights and Method of Payment.

    (a) Rights granted under the Plan will be exercisable periodically on
specified dates as determined by the Board of Directors.

    (b) The method of payment for Shares purchased upon exercise of rights
granted hereunder shall be through regular payroll deductions or by lump sum
cash payment or both, as determined by the Board of Directors. No interest shall
be paid upon payroll deductions unless specifically provided for by the Board of
Directors.

    (c) Any payments received by the Company from a participating employee and
not utilized for the purchase of Shares upon exercise of a right granted
hereunder shall be promptly returned to such employee by the Company after
termination of the right to which the payment relates.

    6. Term of Rights.

    The total period from an Offering Date to the last date on which rights
granted on that Offering Date are exercisable (the "Offering Period") shall in
no event be longer than twenty-seven (27) months. The Board of Directors when it
authorizes an Offering may designate one or more exercise periods during the
Offering Period. Rights granted on an Offering Date shall be exercisable in full
on the Offering Date or in such proportion on the last day of each exercise
period as the Board of Directors determines.

    7. Shares Subject to the Plan.

    No more than Nine Hundred Thousand (900,000) Shares may be sold pursuant to
rights granted under the Plan. Appropriate adjustments in the above figure, in
the number of Shares covered by outstanding rights granted hereunder, in the
exercise price of the rights and in the maximum number of Shares which an
employee may purchase (pursuant to Section 9 below) shall be made to give effect
to any mergers, consolidations, reorganizations, recapitalizations, stock
splits, stock dividends or other relevant changes in the capitalization of the
Company occurring after the effective date of the Plan, provided that no
fractional Shares shall be subject to a right and each right shall be adjusted
downward to the nearest full Share. Any agreement of merger or consolidation
will include provisions for protection of the then existing rights of
participating employees under the Plan. Either authorized and unissued Shares or
issued Shares heretofore or hereafter reacquired by the Company may be

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made subject to rights under the Plan. If for any reason any right under the
Plan terminates in whole or in part, Shares subject to such terminated right
may again be subjected to a right under the Plan.

    8. Limitations on Grants.

    (a) No employee shall be granted a right hereunder if such employee,
immediately after the right is granted, would own stock or rights to purchase
stock possessing five percent (5%) or more of the total combined voting power or
value of all classes of stock of the Company, or of any subsidiary, computed in
accordance with Section 423(b)(3) of the Code.

    (b) No employee shall be granted a right which permits his right to purchase
shares under all employee stock purchase plans of the Company and its
subsidiaries to accrue at a rate which exceeds twenty-five thousand dollars
($25,000) (or such other maximum as may be prescribed from time to time by the
Code) of the fair market value of such Shares (determined at the time such right
is granted) for each calendar year in which such right is outstanding at any
time in accordance with the provisions of Section 423(b)(8) of the Code.

    (c) No right granted to any participating employee under an Offering, when
aggregated with rights granted under any other Offering still exercisable by the
participating employee, shall cover more shares than may be purchased at an
exercise price equal to fifteen percent (15%) of the employee's annual rate of
compensation on the date the employee elects to participate in the Offering or
such lesser percentage as the Board of Directors may determine.

    9. Limit on Participation.

    Participation in an Offering shall be limited to eligible employees who
elect to participate in such Offering in the manner, and within the time
limitations, established by the Board of Directors when it authorizes the
Offering.

    10. Cancellation of Election to Participate.

    An employee who has elected to participate in an Offering may cancel such
election as to all (but not part) of the unexercised rights granted under
such Offering by giving written notice of such cancellation to the Company
before the expiration of any exercise period. Any amounts paid by the
employee for the Shares or withheld for the purchase of Shares from the
employee's compensation through payroll deductions shall be paid to the
employee, without interest, unless otherwise determined by the Board of
Directors, upon such cancellation.

    11. Termination of Employment.

    Upon the termination of employment for any reason, including the death of
the employee, before the date on which any rights granted under the Plan are
exercisable, all such rights shall immediately terminate and amounts paid by the
employee for the Shares or withheld for the purchase of Shares from the
employee's compensation through payroll

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deductions shall be paid to the employee or to the employee's estate, without
interest unless otherwise determined by the Board of Directors.

    12. Employees' Rights as Shareholders.

    No participating employee shall have any rights as a shareholder in the
Shares covered by a right granted hereunder until such right has been exercised,
full payment has been made for the corresponding Shares and the Share
certificate is actually issued.

    13. Rights Not Transferable.

    Rights under the Plan are not assignable or transferable by a participating
employee and are exercisable only by the employee.

    14. Amendments to or Discontinuation of the Plan.

    The Board of Directors of the Company shall have the right to amend, modify
or terminate the Plan at any time without notice; provided, however, that the
then existing rights of all participating employees shall not be adversely
affected thereby, and provided further that, subject to the provisions of
Section 7 above, no such amendment to the Plan shall, without the approval of
the shareholders of the Company, increase the total number of Shares which may
be offered under the Plan.

    15. Effective Date and Approvals.

    This Plan became effective on May 1, 1993, the date it was adopted by the
Board of Directors. This Plan was approved by the shareholders of the Company on
June 25, 1993.

    The Company's obligation to offer, sell and deliver its Shares under the
Plan is subject to (i) the approval of any governmental authority required in
connection with the authorized issuance or sale of such Shares, (ii)
satisfaction of the listing requirements of any national securities exchange on
which the Shares are then listed and (iii) compliance, in the opinion of the
Company's counsel with, all applicable federal and state securities and other
laws.

    16. Term of Plan.

    No rights shall be granted under the Plan after May 1, 2003.

    17. Administration of the Plan.

    The Board of Directors or any committee or person(s) to whom it delegates
its authority (the "Administrator") shall administer, interpret and apply all
provisions of the Plan as it deems necessary to meet special circumstances not
anticipated or covered expressly by the Plan. Nothing contained in this Section
shall be deemed to authorize the Administrator to alter or administer the
provisions of the Plan in a manner inconsistent with the provisions of Section
423 of the Code.

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