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                                                              EXHIBIT 10.77

                                PROMISSORY NOTE
 
$25,000  Palo Alto, California
                                                            December 6, 1995
 
     FOR VALUE RECEIVED, the undersigned, Howard Palefsky ("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 twenty-five thousand dollars ($25
,000).
 
     Interest will be accrued quarterly on the outstanding principal balance at
the lower of: Ten percent (10%) per annum, or the prime rate as of the last day
of the calendar quarter, as reported in the Wall Street Journal. All accrued
interest will be paid annually, on September 1 of each year.
 
     Fifty percent (50%) of each performance bonus (e.g., the MBR bonus) awarded
to the undersigned will be retained by the Company and deducted from the loan
balance for the next five years, until the loan is paid in full; and upon the
fifth anniversary date of the note, the entire balance of principal and interest
if any, will be due and payable.
 
     If Borrower's employment 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. Borrower hereby acknowledges that the
amounts of principal reduced hereunder and any interest imputed to Borrower
under the Internal Revenue Code of 1986, as amended, will be taxable income to
Borrower and, as such will be subject to all applicable federal state and local
tax withholding requirements.
 
     As security for the payment of the principal and accrued interest on this
Note and any renewal, extension or modification thereof, Borrower hereby grants
to Lender a first priority security interest in any and all shares of Lender's
capital stock currently held or hereafter acquired by or on behalf of Borrower
("Pledged Shares"). Borrower covenants and agrees to promptly deliver all
certificates or other evidences of Pledged Shares to Lender and to take such
further actions and execute such further documents as may be necessary for
Lender to perfect its security interest in the Pledged Shares.
 
     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.
 
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/s/  REID W. DENNIS                      /s/  HOWARD PALELSKY
Acknowledged and accepted by:
Reid W. Dennis                           December 11, 1995
Chairman of Emeritus
  Chairman of Executive Committee
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