<PAGE>   1
        This document consists of 13 pages, of which this page is number 1. The
        Index to Exhibits is on page 9.

   As filed with the Securities and Exchange Commission on December 10, 1997.

                                                 Registration No. 333-__________


                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                             ----------------------

                                    FORM S-8

                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933

                              ---------------------

                          CELTRIX PHARMACEUTICALS, INC.
             (Exact name of Registrant as specified in its charter)

                DELAWARE                             94-3121462
        (State of Incorporation)        (I.R.S. Employer Identification No.)

                            3055 PATRICK HENRY DRIVE
                           SANTA CLARA, CA 95054-1814
                    (Address of principal executive offices)

                              ---------------------

                             1991 STOCK OPTION PLAN
                            (Full title of the Plan)

                              ---------------------

                                 Andreas Sommer
                      President and Chief Executive Officer
                          Celtrix Pharmaceuticals, Inc.
                            3055 Patrick Henry Drive
                           Santa Clara, CA 95054-1814
                                 (408) 988-2500
            (Name, address and telephone number of agent for service)

                              ---------------------

                                   Copies to:
                              EDMUND S. RUFFIN, JR.
                                Venture Law Group
                           A Professional Corporation
                               2800 Sand Hill Road
                          Menlo Park, California 94025
                                 (415) 854-4488

<PAGE>   2


<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------
                                CALCULATION OF REGISTRATION FEE
-----------------------------------------------------------------------------------------------
                                                          Proposed     Proposed
                                                          Maximum      Maximum
                                                          Offering     Aggregate    Amount of
                                        Amount to be      Price Per    Offering    Registration
Title of Securities to be Registered    Registered(1)       Share       Price          Fee
-----------------------------------------------------------------------------------------------
<S>                                    <C>                <C>                      <C>
1991 STOCK OPTION PLAN
  Common Stock,
  $0.01 par value...................   1,500,000 Shares   $ 2.0625 (2) $ 3,093,750   $ 1,066.81
-----------------------------------------------------------------------------------------------
    TOTAL (3)                          1,500,000 Shares                $ 3,093,750   $ 1,066.81
</TABLE>




------------------

(1) This Registration Statement shall also cover any additional shares of Common
Stock which become issuable under the plan being registered pursuant to this
Registration Statement by reason of any stock dividend, stock split,
recapitalization or any other similar transaction effected without the receipt
of consideration which results in an increase in the number of the Registrant's
outstanding shares of Common Stock.

(2) Estimated in accordance with Rule 457(c) and 457(h) under the Securities Act
of 1933 (the "Securities Act") solely for the purpose of calculating the
registration fee. The computation with respect to unissued options is based upon
the average high and low sale prices of the Common Stock as reported on the
Nasdaq National Market on December 9, 1997.

(3) Excludes all shares previously registered under Registrant's 1991 Stock
Option Plan on Form S-8 (Registration No. 33-55482).




                                       2
<PAGE>   3




PART II:  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3  INFORMATION INCORPORATED BY REFERENCE


        The following documents filed with the Securities and Exchange
Commission (the "Commission") are hereby incorporated by reference:

        1. The Registrant's Annual Report on Form 10-K for the year ended March
31, 1997.

        2. The Registrant's definitive Proxy Statement dated July 21, 1997,
filed with the Commission in connection with the September 9, 1997 Annual
Meeting of Stockholders of the Registrant.

        3. The Registrant's Quarterly Reports on Form 10-Q for the quarters
ended June 30, 1997 and September 30, 1997, respectively.

        4. The description of the Registrant's Common Stock set forth in the
Registrant's Registration Statement on Form 10 filed with the Commission on
January 24, 1991.

        All documents subsequently filed by the Registrant pursuant to Sections
13(a), 13(c), 14 and 15(d) of the Exchange Act, prior to the filing of a
post-effective amendment which indicates that all securities offered have been
sold or which de-registers all securities then remaining unsold, shall be deemed
to be incorporated by reference in this Registration Statement and to be part
hereof from the date of filing of such documents.

ITEM 4  DESCRIPTION OF SECURITIES

        Not Applicable.

ITEM 5  INTERESTS OF NAMED EXPERTS AND COUNSEL

        Not Applicable.

ITEM 6  INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Section 145(a) of the Delaware General Corporation Law (the "DGCL")
provides in relevant part that "a corporation may indemnify any person who was
or is a party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, administrative or
investigative (other than an action by or in the right of the corporation), by
reason of the fact that he is or was a director, officer, employee or agent of
another corporation, partnership, joint venture, trust or other enterprise,
against expenses (including attorneys' fees), judgments, fines and amounts paid
in settlement actually and reasonably incurred by him in connection with such
action, suit or proceeding if he acted in good




                                       3
<PAGE>   4

faith and in a manner he reasonably believed to be in or not opposed to the best
interest of the corporation, and, with respect to any criminal action or
proceeding, had no reasonable cause to believe his conduct was unlawful." With
respect to derivative actions, Section 145(b) of the DGCL provides in relevant
part that "[a] corporation may indemnify any person who was or is a party or is
threatened to be made a party to any threatened, pending or completed action or
suit by or in the right of the corporation to procure a judgment in its
favor...[by reason of his service in one of the capacities specified in the
preceding sentence] against expenses (including attorneys' fees) actually and
reasonably incurred by him in connection with the defense or settlement of such
action or suit if he acted in good faith and in a manner he reasonably believed
to be in or not opposed to the best interest of the corporation and except that
no indemnification shall be made in respect of any claim, issue or matter as to
which such person shall have been adjudged to be liable to the corporation
unless and only to the extent that the Court of Chancery or the court in which
such action or suit was brought shall determine upon application that, despite
the adjudication of liability but in view of all the circumstances of the case,
such person is fairly and reasonably entitled to indemnity for such expenses
which the Court of Chancery or such other court shall deem proper."

         The Registrant's Certificate of Incorporation provides that each person
who is or was or who had agreed to become a director or officer of the
Registrant or who had agreed at the request of the Registrant's Board of
Directors or an officer of the Registrant to serve as an employee or agent of
the Registrant or as a director, officer, employee or agent of another
corporation, partnership, joint venture, trust or other enterprise, shall be
indemnified by the Registrant to the full extent permitted by the DGCL or any
other applicable laws. Such Certificate of Incorporation also provides that no
amendment or repeal of such Certificate shall apply to or have any effect on the
right to indemnification permitted or authorized thereunder for or with respect
to claims asserted before or after such amendment or repeal arising from acts or
omissions occurring in whole or in part before the effective date of such
amendment or repeal.

         The Registrant's Bylaws provide that the Registrant shall indemnify to
the full extent authorized by law any person made or threatened to be made a
party to an action or a proceeding, whether criminal, civil, administrative or
investigative, by reason of the fact that he was or is a director, officer, or
employee of the Registrant or serves or served any other enterprise as a
director, officer or employee at the request of the Registrant.

         The Registrant has entered or will enter into indemnification
agreements with its directors and certain of its officers. The Registrant has
purchased insurance on behalf of its officers and directors against losses
arising from any claim asserted against or incurred by such individuals in any
such capacity, subject to certain exclusions.

Item 7.  Exemption from Registration Claimed.  Not applicable.



                                       4
<PAGE>   5





Item 8.  Exhibits.

<TABLE>
<CAPTION>
         Exhibit
         Number
         ------
          <S>        <C>
           4.1       1991 Employee Stock Option Plan and form of related agreements.
           5.1       Opinion of Venture Law Group, a Professional Corporation.
          23.1       Consent of Venture Law Group, a Professional Corporation (included
                     in Exhibit 5.1).
          23.2       Consent of Ernst & Young LLP, Independent Auditors.
          24.1       Powers of Attorney.(See page 8)
</TABLE>

Item 9.  Undertakings.

        The undersigned Registrant hereby undertakes:

               (1)    to file, during any period in which offers or sales are
        being made, a post-effective amendment to this registration statement to
        include any material information with respect to the plan of
        distribution not previously disclosed in the registration statement or
        any material change to such information in the registration statement.

               (2)    that, for purposes of determining any liability under the
        Securities Act, each such post-effective amendment shall be deemed to be
        a new registration statement relating to the securities offered therein,
        and the offering of such securities at that time shall be deemed to be
        the initial bona fide offering thereof.

               (3)    to remove from registration by means of a post-effective
        amendment any of the securities being registered which remain unsold at
        the termination of the offering.

        The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act, each filing of the
Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act that is incorporated by reference in the registration statement
shall be deemed to be a new registration statement relating to the securities
offered therein, and the offering of such securities at that time shall be
deemed to be the initial bona fide offering thereof.

        Insofar as the indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the Securities Act and
is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than



                                       5
<PAGE>   6

the payment by the Registrant of expenses incurred or paid by a director,
officer or controlling person of the Registrant in a successful defense of any
action, suit or proceeding) is asserted by such director, officer or controlling
person in connection with the securities being registered hereunder, the
Registrant will, unless in the opinion of its counsel the matter has been
settled by controlling precedent, submit to a court of appropriate jurisdiction
the question of whether such indemnification by it is against public policy as
expressed in the Securities Act and will be governed by the final adjudication
of such issue.



                           [Signature page to follow.]












                                       6
<PAGE>   7



                                   SIGNATURES


        Pursuant to the requirements of the Securities Act of 1933, the
Registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Santa Clara, State of California, on this 10th day of
December 1997.

                                        CELTRIX PHARMACEUTICALS, INC.



                                        By: /s/ ANDREAS SOMMER
                                            -----------------------------------
                                            Andreas Sommer, President and Chief
                                            Executive Officer









                                       7
<PAGE>   8



                                POWER OF ATTORNEY

        KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Andreas Sommer and Donald D. Huffman and
each of them acting individually, as his attorney-in-fact, each with full power
of substitution and resubstitution, and in his name, place or stead, in any and
all capacities, to sign any amendments to this Registration Statement on Form
S-8, and to file the same, with exhibits thereto and other documents in
connection therewith, with the Securities and Exchange Commission, granting unto
said attorney-in-fact and agent, full power and authority to do and perform each
and every act and thing requisite and necessary to be done in and about the
premises, as fully as he might or could do in person, and ratifying and
confirming all that said attorney-in-fact and agent, or his substitute or
substitutes, may do or cause to be done by virtue hereof.

        Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the dates indicated.


<TABLE>
<CAPTION>
           Signature                             Title                         Date
           ---------                             -----                         ----
<S>                               <C>                                     <C>
/s/ ANDREAS SOMMER                President, Chief Executive Officer      December 10, 1997
-----------------------------     and Director (Principal
Andreas Sommer                    Executive Officer)

/s/ DONALD D. HUFFMAN             Vice President, Finance and             December 10, 1997
-----------------------------     Administration, Chief Financial
Donald D. Huffman                 Officer and Assistant Secretary
                                  (Principal Financial and
                                  Accounting Officer)

/s/ JAMES E. THOMAS               Chairman of the Board                   December 10, 1997
-----------------------------
James E. Thomas

/s/ HENRY E. BLAIR                Director                                December 10, 1997
-----------------------------
Henry E. Blair

/s/ BARRY M. SHERMAN              Director                                December 10, 1997
-----------------------------
Barry M. Sherman
</TABLE>







                                       8

<PAGE>   9



                                INDEX TO EXHIBITS


<TABLE>
<CAPTION>
 Exhibit                                                                             Page
 Number                                                                               No.
 ------                                                                               ---
  <S>       <C>                                                                       <C>
   4.1*     1991 Employee Stock Option Plan and form of agreements.
   5.1      Opinion of Venture Law Group, a Professional Corporation.
  23.1      Consent of Venture Law Group, a Professional Corporation (included
            in Exhibit 5.1).
  23.2      Consent of Ernst & Young LLP, Independent Auditors.
  24.1      Powers of Attorney.(See page 8)
</TABLE>

--------------------

* Incorporated by reference as filed with Registrant's Proxy Statement dated
  July 21, 1997.
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 17592}]
{"company-data": {"conformed-name": "CELTRIX PHARMACEUTICALS INC", "cik": "0000871395", "assigned-sic": "2834", "irs-number": "943121462", "state-of-incorporation": "DE", "fiscal-year-end": "0331"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-41883", "film-number": "97735571"}, "business-address": {"street1": "3055 PATRICK HENRY DR", "city": "SANTA CLARA", "state": "CA", "zip": "95054", "phone": "4089882500"}, "mail-address": {"street2": "3055 PATRICK HENRY DRIVE", "city": "SANTA CLARA", "state": "CA", "zip": "95054"}, "former-company": {"former-conformed-name": "CELTRIX LABORATORIES INC", "date-changed": "19600201"}}
1
        This document consists of 13 pages, of which this page is number 1. The
        Index to Exhibits is on page 9.

   As filed with the Securities and Exchange Commission on December 10, 1997.

                                                 Registration No. 333-__________

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                             ----------------------

                                    FORM S-8

                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933

                              ---------------------

                          CELTRIX PHARMACEUTICALS, INC.
             (Exact name of Registrant as specified in its charter)

                DELAWARE                             94-3121462
        (State of Incorporation)        (I.R.S. Employer Identification No.)

                            3055 PATRICK HENRY DRIVE
                           SANTA CLARA, CA 95054-1814
                    (Address of principal executive offices)

                              ---------------------

                             1991 STOCK OPTION PLAN
                            (Full title of the Plan)

                              ---------------------

                                 Andreas Sommer
                      President and Chief Executive Officer
                          Celtrix Pharmaceuticals, Inc.
                            3055 Patrick Henry Drive
                           Santa Clara, CA 95054-1814
                                 (408) 988-2500
            (Name, address and telephone number of agent for service)

                              ---------------------

                                   Copies to:
                              EDMUND S. RUFFIN, JR.
                                Venture Law Group
                           A Professional Corporation
                               2800 Sand Hill Road
                          Menlo Park, California 94025
                                 (415) 854-4488
2
-----------------------------------------------------------------------------------------------
                                CALCULATION OF REGISTRATION FEE
-----------------------------------------------------------------------------------------------
                                                          Proposed     Proposed
                                                          Maximum      Maximum
                                                          Offering     Aggregate    Amount of
                                        Amount to be      Price Per    Offering    Registration
Title of Securities to be Registered    Registered(1)       Share       Price          Fee
-----------------------------------------------------------------------------------------------
1991 STOCK OPTION PLAN
  Common Stock,
  $0.01 par value...................   1,500,000 Shares   $ 2.0625 (2) $ 3,093,750   $ 1,066.81
-----------------------------------------------------------------------------------------------
    TOTAL (3)                          1,500,000 Shares                $ 3,093,750   $ 1,066.81
------------------

(1) This Registration Statement shall also cover any additional shares of Common
Stock which become issuable under the plan being registered pursuant to this
Registration Statement by reason of any stock dividend, stock split,
recapitalization or any other similar transaction effected without the receipt
of consideration which results in an increase in the number of the Registrant's
outstanding shares of Common Stock.

(2) Estimated in accordance with Rule 457(c) and 457(h) under the Securities Act
of 1933 (the "Securities Act") solely for the purpose of calculating the
registration fee. The computation with respect to unissued options is based upon
the average high and low sale prices of the Common Stock as reported on the
Nasdaq National Market on December 9, 1997.

(3) Excludes all shares previously registered under Registrant's 1991 Stock
Option Plan on Form S-8 (Registration No. 33-55482).

                                       2
3

PART II:  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3  INFORMATION INCORPORATED BY REFERENCE

        The following documents filed with the Securities and Exchange
Commission (the "Commission") are hereby incorporated by reference:

        1. The Registrant's Annual Report on Form 10-K for the year ended March
31, 1997.

        2. The Registrant's definitive Proxy Statement dated July 21, 1997,
filed with the Commission in connection with the September 9, 1997 Annual
Meeting of Stockholders of the Registrant.

        3. The Registrant's Quarterly Reports on Form 10-Q for the quarters
ended June 30, 1997 and September 30, 1997, respectively.

        4. The description of the Registrant's Common Stock set forth in the
Registrant's Registration Statement on Form 10 filed with the Commission on
January 24, 1991.

        All documents subsequently filed by the Registrant pursuant to Sections
13(a), 13(c), 14 and 15(d) of the Exchange Act, prior to the filing of a
post-effective amendment which indicates that all securities offered have been
sold or which de-registers all securities then remaining unsold, shall be deemed
to be incorporated by reference in this Registration Statement and to be part
hereof from the date of filing of such documents.

ITEM 4  DESCRIPTION OF SECURITIES

        Not Applicable.

ITEM 5  INTERESTS OF NAMED EXPERTS AND COUNSEL

        Not Applicable.

ITEM 6  INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Section 145(a) of the Delaware General Corporation Law (the "DGCL")
provides in relevant part that "a corporation may indemnify any person who was
or is a party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, administrative or
investigative (other than an action by or in the right of the corporation), by
reason of the fact that he is or was a director, officer, employee or agent of
another corporation, partnership, joint venture, trust or other enterprise,
against expenses (including attorneys' fees), judgments, fines and amounts paid
in settlement actually and reasonably incurred by him in connection with such
action, suit or proceeding if he acted in good

                                       3
4

faith and in a manner he reasonably believed to be in or not opposed to the best
interest of the corporation, and, with respect to any criminal action or
proceeding, had no reasonable cause to believe his conduct was unlawful." With
respect to derivative actions, Section 145(b) of the DGCL provides in relevant
part that "[a] corporation may indemnify any person who was or is a party or is
threatened to be made a party to any threatened, pending or completed action or
suit by or in the right of the corporation to procure a judgment in its
favor...[by reason of his service in one of the capacities specified in the
preceding sentence] against expenses (including attorneys' fees) actually and
reasonably incurred by him in connection with the defense or settlement of such
action or suit if he acted in good faith and in a manner he reasonably believed
to be in or not opposed to the best interest of the corporation and except that
no indemnification shall be made in respect of any claim, issue or matter as to
which such person shall have been adjudged to be liable to the corporation
unless and only to the extent that the Court of Chancery or the court in which
such action or suit was brought shall determine upon application that, despite
the adjudication of liability but in view of all the circumstances of the case,
such person is fairly and reasonably entitled to indemnity for such expenses
which the Court of Chancery or such other court shall deem proper."

         The Registrant's Certificate of Incorporation provides that each person
who is or was or who had agreed to become a director or officer of the
Registrant or who had agreed at the request of the Registrant's Board of
Directors or an officer of the Registrant to serve as an employee or agent of
the Registrant or as a director, officer, employee or agent of another
corporation, partnership, joint venture, trust or other enterprise, shall be
indemnified by the Registrant to the full extent permitted by the DGCL or any
other applicable laws. Such Certificate of Incorporation also provides that no
amendment or repeal of such Certificate shall apply to or have any effect on the
right to indemnification permitted or authorized thereunder for or with respect
to claims asserted before or after such amendment or repeal arising from acts or
omissions occurring in whole or in part before the effective date of such
amendment or repeal.

         The Registrant's Bylaws provide that the Registrant shall indemnify to
the full extent authorized by law any person made or threatened to be made a
party to an action or a proceeding, whether criminal, civil, administrative or
investigative, by reason of the fact that he was or is a director, officer, or
employee of the Registrant or serves or served any other enterprise as a
director, officer or employee at the request of the Registrant.

         The Registrant has entered or will enter into indemnification
agreements with its directors and certain of its officers. The Registrant has
purchased insurance on behalf of its officers and directors against losses
arising from any claim asserted against or incurred by such individuals in any
such capacity, subject to certain exclusions.

Item 7.  Exemption from Registration Claimed.  Not applicable.

                                       4
5

Item 8.  Exhibits.
Exhibit
         Number
         ------
4.1       1991 Employee Stock Option Plan and form of related agreements.
           5.1       Opinion of Venture Law Group, a Professional Corporation.
          23.1       Consent of Venture Law Group, a Professional Corporation (included
                     in Exhibit 5.1).
          23.2       Consent of Ernst & Young LLP, Independent Auditors.
          24.1       Powers of Attorney.(See page 8)
Item 9.  Undertakings.

        The undersigned Registrant hereby undertakes:

               (1)    to file, during any period in which offers or sales are
        being made, a post-effective amendment to this registration statement to
        include any material information with respect to the plan of
        distribution not previously disclosed in the registration statement or
        any material change to such information in the registration statement.

               (2)    that, for purposes of determining any liability under the
        Securities Act, each such post-effective amendment shall be deemed to be
        a new registration statement relating to the securities offered therein,
        and the offering of such securities at that time shall be deemed to be
        the initial bona fide offering thereof.

               (3)    to remove from registration by means of a post-effective
        amendment any of the securities being registered which remain unsold at
        the termination of the offering.

        The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act, each filing of the
Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act that is incorporated by reference in the registration statement
shall be deemed to be a new registration statement relating to the securities
offered therein, and the offering of such securities at that time shall be
deemed to be the initial bona fide offering thereof.

        Insofar as the indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the Securities Act and
is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than

                                       5
6

the payment by the Registrant of expenses incurred or paid by a director,
officer or controlling person of the Registrant in a successful defense of any
action, suit or proceeding) is asserted by such director, officer or controlling
person in connection with the securities being registered hereunder, the
Registrant will, unless in the opinion of its counsel the matter has been
settled by controlling precedent, submit to a court of appropriate jurisdiction
the question of whether such indemnification by it is against public policy as
expressed in the Securities Act and will be governed by the final adjudication
of such issue.

                           [Signature page to follow.]

                                       6
7

                                   SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, the
Registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Santa Clara, State of California, on this 10th day of
December 1997.

                                        CELTRIX PHARMACEUTICALS, INC.

                                        By: /s/ ANDREAS SOMMER
                                            -----------------------------------
                                            Andreas Sommer, President and Chief
                                            Executive Officer

                                       7
8

                                POWER OF ATTORNEY

        KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Andreas Sommer and Donald D. Huffman and
each of them acting individually, as his attorney-in-fact, each with full power
of substitution and resubstitution, and in his name, place or stead, in any and
all capacities, to sign any amendments to this Registration Statement on Form
S-8, and to file the same, with exhibits thereto and other documents in
connection therewith, with the Securities and Exchange Commission, granting unto
said attorney-in-fact and agent, full power and authority to do and perform each
and every act and thing requisite and necessary to be done in and about the
premises, as fully as he might or could do in person, and ratifying and
confirming all that said attorney-in-fact and agent, or his substitute or
substitutes, may do or cause to be done by virtue hereof.

        Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the dates indicated.
Signature                             Title                         Date
           ---------                             -----                         ----
/s/ ANDREAS SOMMER                President, Chief Executive Officer      December 10, 1997
-----------------------------     and Director (Principal
Andreas Sommer                    Executive Officer)

/s/ DONALD D. HUFFMAN             Vice President, Finance and             December 10, 1997
-----------------------------     Administration, Chief Financial
Donald D. Huffman                 Officer and Assistant Secretary
                                  (Principal Financial and
                                  Accounting Officer)

/s/ JAMES E. THOMAS               Chairman of the Board                   December 10, 1997
-----------------------------
James E. Thomas

/s/ HENRY E. BLAIR                Director                                December 10, 1997
-----------------------------
Henry E. Blair

/s/ BARRY M. SHERMAN              Director                                December 10, 1997
-----------------------------
Barry M. Sherman
8
9

                                INDEX TO EXHIBITS
Exhibit                                                                             Page
 Number                                                                               No.
 ------                                                                               ---
4.1*     1991 Employee Stock Option Plan and form of agreements.
   5.1      Opinion of Venture Law Group, a Professional Corporation.
  23.1      Consent of Venture Law Group, a Professional Corporation (included
            in Exhibit 5.1).
  23.2      Consent of Ernst & Young LLP, Independent Auditors.
  24.1      Powers of Attorney.(See page 8)
--------------------

* Incorporated by reference as filed with Registrant's Proxy Statement dated
  July 21, 1997.