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                                                                  EXHIBIT 10.85

                                  ***REPAID***

                                 PROMISSORY NOTE

$1,000,000                                                Palo Alto, California
                                                                  July 22, 1996


         FOR VALUE RECEIVED, the undersigned, Reid W. Dennis ("Borrower"),
promises to pay to Collagen Corporation, a Delaware corporation ("Lender"), or
order, at 2500 Faber Place, Palo Alto, CA 94303, or at such other place as
Lender may from time to time designate in writing, the sum of one million
dollars ($1,000,000).

         Interest will be accrued on the outstanding principal balance on a
daily basis at the rate of 8.25% per annum based on a 365-day year. The
outstanding balance of principal and accrued interest of this Note shall be due
and payable on September 29, 1996, at which time all accrued interest shall be
compounded and thereafter all accrued interest shall be compounded annually on
each anniversary of the date hereof until the outstanding balance of this Note
is paid in full.

         If Borrower's relationship with the Lender terminates for any reason,
the then outstanding principal balance of this Note, and interest accrued
thereon shall become due and payable immediately. Repayment of this Note shall
be unsecured but the holder hereof shall have full recourse against Borrower.

         Amounts due under this Note shall be payable in lawful money of the
United States of America and in immediately available funds. All payments under
this Note shall be applied first to any accrued and unpaid interest and then to
principal. Borrower shall have the right to pay, without penalty or premium, all
or any portion of the outstanding principal amount of this Note at any time.

         Borrower waives presentment, protest and demand, and notice of protest,
demand, dishonor and nonpayment of this Note and diligence in taking any action
to collect any amounts owing under this Note by proceeding against any of the
rights securing the payment of this Note. If action is instituted on this Note,
Borrower agrees to pay such reasonable sum as attorney's fees as the court may
fix and award in such action.

         This Note shall be governed by and construed in accordance with the
laws of the State of California.

         IN WITNESS WHEREOF, Borrower has executed this Note as of the date
first written above.
                                          /s/ Reid W. Dennis
                                          _____________________________________
                                          Reid W. Dennis
/s/ William G. Davis
__________________________________
Acknowledged and accepted by:
William G. Davis
Chairman, Human Resource Committee
of the Board of Directors