Filed by Genzyme Corporation
                          Pursuant to Rule 425 under the Securities Act of 1933
                                       and deemed filed pursuant to Rule 14a-12
                                         of the Securities Exchange Act of 1934

                                               Subject Company: Biomatrix, Inc.

                                               Registration File No.: 333-34972


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Investors are urged to read the joint proxy statement/prospectus relating to the
transaction described below because it contains important information. The joint
proxy statement/prospectus was filed with the Securities and Exchange Commission
and, along with the documents incorporated by reference into that document, may
be obtained free of charge at the commission's Web site (www.sec.gov). The joint
proxy statement/prospectus and these other documents may also be obtained for
free from Genzyme or Biomatrix, as the case may be. Requests to Genzyme should
be directed to Genzyme Corporation, One Kendall Square, Building 1400,
Cambridge, Massachusetts 02139, Attn: Investor Relations, (617) 252-7500, or you
can access documents on it's Web site (www.genzyme.com). Requests to Biomatrix
should be directed to Biomatrix, Inc. 65 Railroad Avenue, Ridgefield, New Jersey
07657, Attn: Investor Relations, (201) 945-9550, or you can access the documents
on its web site (www.biomatrix.com). Genzyme, Biomatrix, their directors,
certain of their executive officers, and certain of their other employees may be
considered participants in the solicitation of proxies in connection with the
proposed creation of Genzyme Biosurgery. Information concerning these
individuals is contained in the joint proxy statement/prospectus filed with the
Securities and Exchange Commission, which remains subject to completion and
amendment.

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This filing contains forward-looking statements, including statements regarding
the consummation of the proposed merger with Biomatrix, the recapitalization of
Genzyme, and the creation of Genzyme Biosurgery and a new publicly-traded stock,
the future growth, impact and success of Genzyme Biosurgery, including
expectations concerning revenue, revenue growth, research and development
expenditures and market capitalization, the development and potential market
introduction of new products and new indications for products, and the expected
allocation of Genzyme Biosurgery common stock and composition of the merger
consideration. These statements are based upon the current assumptions of our
management and are only expectations of future results. These statements are
also subject to risks and uncertainties, and our actual results may differ
significantly from those that are described in this presentation. These risks
and uncertainties include conditions in the financial markets relevant to the
proposed merger and recapitalization, the likelihood of regulatory and other
approvals of the transactions, the operational integration and other risks
generally associated with mergers and recapitalizations, the results of
preclinical and clinical development efforts, market acceptance of Genzyme
Biosurgery's products and services, the availability of third-party
reimbursement for Genzyme Biosurgery's products, the ability of Genzyme
Biosurgery and/or its partners to successfully commercialize products, the
ability of Genzyme Biosurgery to obtain and maintain distribution arrangements,
the accuracy of information about the biosurgery market, and the competitive
environment for the biosurgery market. We have filed more detailed descriptions
of these risks and uncertainties in some of our recent filings with the
Securities and Exchange Commission, including in our Registration Statement on
Form S-4 filed on April 18, 2000, and any amendments thereto, under the heading
"Risk Factors." We encourage you to carefully review these descriptions.

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[The following is the text of updated slides that comprise a portion of a slide
show being presented in meetings with analysts, potential investors and others
and which was previously filed pursuant to Rule 425 on of the Securities Act on
September 22, 2000.]


SLIDE:





Genzyme Biosurgery: A Strong Business

      -     Estimated revenues of $225M- $235M in 2000

            -     24 major marketed products

            -     7 early life cycle products that account for $135M in revenue

      -     Target revenue growth of approximately 15% in 2001

      -     Break-even on an operating basis in 2001 (before amortization)

      -     Robust pipeline and global infrastructure