AMENDMENT NO.1 TO LICENSING AGREEMENT
                                
     This Amendment No.1 dated as of January 22, 1999 to that certain Licensing
Agreement (this  "Amendment"), dated as of March 31, 1995, by and between 
EMBRYO DEVELOPMENT CORPORATION, a Delaware corporation (the "Company" or 
"Licensee"), and LLOYD A. MARKS, M.D.  (the "Licensor").
  
                    W I T N E S S E T H :
                               
                             
     WHEREAS, the Company and the Licensor have entered into a Licensing 
Agreement dated as of March 31, 1995 (the "Licensing Agreement"), whereby the 
Licensor has licensed the exclusive rights to develop, manufacture and sell 
products covered by U.S. Patent No. 5,256,152 (the "Patent") also known as
the Safety Needle and Method for Using Same (the "Invention").
  
     WHEREAS, the Company and the Licensor desire to amend the Licensing 
Agreement to effect changes provided for herein.
  
     NOW, THEREFORE, in consideration of the premises and mutual covenants 
contained herein,  the receipt and sufficiency of which is hereby acknowledged ,
the parties hereto agree as follows:
  
     1.   Effective as of the date hereof, the Licensing Agreement is hereby 
amended by eliminating the "Minimum Payment Obligation," as that term is defined
in the Licensing Agreement under Section 5.  The last such payment due by 
Licensee shall be the payment which was due in September 30,1998 in the 
amount of $50,000.  Such payment shall be made upon the execution of this 
Amendment.   If this payment is not made or the funds associated with this 
payment are not available to Licensor within thirty days from the date of 
this Amendment then this entire Amendment shall be null and void.
  
     2.   In consideration for eliminating Minimum Payment Obligation, the 
parties hereto agree to the following: 
          
          a)    An increase in the amount of the Royalty as defined in the
          License Agreement under Section 4.2 to 10%;  
     
          b)   The Company shall pay to Licensor, in lieu of any and all other 
          minimum Royalty obligations under the Licensing Agreement, a 
          maximum aggregate sum of four hundred and fifty thousand dollars 
         ($450,000) to be paid as follows:
     
               (i)  $2,500 per month until no balance remains, the first 
          payment to be made in February 1, 1999.  Subsequent payments shall 
          be made on the first of each month thereafter.  If such payments 
          are not made the Company shall be deemed in breach of the Amendment if
          such amounts are not made current within five (5) days of receipt 
          of written notice of breach by Licensor.  Any such amount which are
          past due shall bear an interest rate of 10% per annum;
               
              (ii) 10% of the net proceeds received by the Company from any
          Capital Raise by the Company subsequent to January 7, 1999 
          excluding the first $600,000 raised during the period January 7, 
          1999 through February 28, 1999.  For purposes of this Amendment, 
          the term "Capital Raise" shall be defined as the sale of any equity
          securities issued by  the Company whether in a private or public 
          transaction, or the proceeds from any  new long-term debt financing of
          the Company, the sale of any of the remaining shares of HDS common 
          stock owned by the Company, or the sale of substantially all of
          the Company's assets.  Such amounts due under this section 2(b)(ii) 
          shall be due thirty days from the time such funds become available to
          the Company and a schedule illustrating the calculation of any 
          amounts due hereunder shall be provided to the Licensor along with 
          any payments.  The Company shall provide the Licensor with notice
          of any such Capital Raise as soon as practicable;
     
             (iii) 10% of the Net Income Before Taxes on a consolidated basis of
          the Company (as defined using generally accepted accounting practices
          typical of the medical device industry), to be paid within 90 days 
          after fiscal year-end; and 

            (iv) Payments made under the provisions of section 2(b) of this 
          Amendment shall not be applied to any amounts due under section 2(a)
          of this Amendment; and
               
             (v)  Any failure by the Company to make any payment under section
          2(b) of this Amendment if not cured within 30 days after receipt of 
          written notice by Licensor shall permit the Licensor to immediately 
          terminate this Amendment and the Licensing Agreement.
               
          The aggregate sum of $450,000 shall not bear any interest.
               
          c)   If the Licensing Agreement is terminated for any reason by the
          Licensor, the remaining balance due under section 2(b) above shall 
          be reduced by the lesser amount of $125,000 or the remaining balance
          due and all possessions owned by the Company related to the Invention,
          including but not limited to documents, engineering reports and 
          drawings, prototypes, molds, models, data, and other information 
          acquired by the Company with respect to the Invention (collectively
          hereinafter referred to as the "Know  How") shall be given to the
          Licensor and become the Licensor's property free and clear of any 
          liens or encumbrances.  If the Company terminates this Amendment or 
          the Licensing Agreement for any reason then the Licensor shall have 
          the option to acquire the Know-How for a reduction in the remaining 
          balance due under section 2(b) above equal to the lesser amount of 
         $125,000 or the remaining balance due.
               
  
         d)   If the Company does not obtain the necessary government approvals
         to market the Invention within 24 months from the date hereof then the 
         License Agreement shall automatically terminate unless the Company is 
         current with all of its obligations under section 2(b) of this 
         Amendment and pays the Licensor  an additional fee of $250,000, paid by
         the last day of the 24th month of the date of this agreement, and 
         thereby extends this regulatory approval requirement by an 
         additional 24 months.  If the Company extends this regulatory 
         approval requirement and the Company does not obtain the necessary 
         government approvals to market the Invention within 48 months from 
         the date hereof then the License Agreement shall automatically
         terminate.
     
         e)   The Licensor acknowledges that this Amendment and the terms 
         contained herein fully satisfy any prior obligations owed to Licensor 
         by the Company including, but not limited to, the Minimum Payment 
         Obligations with respect to the Invention and any other products or 
         inventions currently or previously licensed by the Company from the 
         Licensor.
  
     3.   This Amendment shall be governed by and construed in accordance with
the laws of the State of New York, without regard to principles of conflicts of
law.
  
     4.   Except as otherwise specifically set forth herein, all of the terms
and provisions of the Licensing Agreement shall remain in full force and effect.
  
     IN WITNESS WHEREOF, the parties have executed this Amendment as of the day
and year first above written.
        

                 EMBRYO DEVELOPMENT CORPORATION
  
                 By:/s/ Matthew Harriton
                    ---------------------  
                 Name: Matthew Harriton
                 Title:  CEO
  
                 /s/ Lloyd Marks
                 _____________________________
                 Llyod A. Marks, M.D.