<PAGE>   1
                                                      Registration No. _________

                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM S-8

                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                   AMERICAN RESIDENTIAL INVESTMENT TRUST, INC.
             (Exact name of registrant as specified in its charter)

            Maryland                                    33-0741174
  (State or other jurisdiction              (I.R.S. employer identification no.)
of incorporation or organization)

                        445 Marine View Avenue, Suite 230
                            Del Mar, California 92014
               (Address of principal executive offices) (Zip code)

                   AMERICAN RESIDENTIAL INVESTMENT TRUST, INC.
                           1997 STOCK INCENTIVE PLAN,
                             1997 STOCK OPTION PLAN,
                       1997 EMPLOYEE STOCK PURCHASE PLAN,
                  AND 1997 OUTSIDE DIRECTORS STOCK OPTION PLAN
                            (Full title of the plan)

                          Clay Strittmatter (Secretary)
                   American Residential Investment Trust, Inc.
                        445 Marine View Avenue, Suite 230
                            Del Mar, California 92014
                     (Name and address of agent for service)


Telephone number, including area code, of agent for service: (619) 350-5008.
This registration statement shall hereafter become effective in accordance with
Rule 462 promulgated under the Securities Act of 1933, as amended (the
"Securities Act").



                                       1
<PAGE>   2
<TABLE>
<CAPTION>
--------------------------------------------------------------------------------------------------------------------------------
                                                 CALCULATION OF REGISTRATION FEE
--------------------------------------------------------------------------------------------------------------------------------
                                                                        Proposed              Proposed
                                                                        maximum                maximum
        Title of Securities to                 Amount to be        offering price per         aggregate            Amount of
         to be registered(1)                   registered               share(2)           offering price(2)    registration fee
----------------------------------------       ------------       ---------------------    ---------------      ----------------
<S>                                            <C>                <C>                      <C>                  <C>
1997 Stock Incentive Plan
Common Stock                                        315,200              $12.50              $ 3,940,000
Par Value $0.01

1997 Stock Option Plan
Common Stock                                        414,200              $15.00              $ 6,213,000
Par Value $0.01                                      60,600              $11.66              $   706,596

1997 Employee Stock Purchase Plan
Common Stock                                         20,000              $ 9.91              $   198,200
Par Value $0.01

1997 Outside Directors Stock Option Plan
Common Stock                                         30,000              $15.00              $   450,000
Par Value $0.01                                      30,000              $11.66              $   349,800

TOTALS                                              870,000                                  $11,857,596           $ 3,498.00
                                                                                                                 ---------------
</TABLE>
----------------------
1    The securities to be registered include options and rights to acquire such
     Common Stock.

2    Estimated pursuant to Rule 457 solely for purposes of calculating the
     registration fee. As to shares subject to outstanding but unexercised
     options under the 1997 Stock Incentive Plan, 1997 Stock Option Plan and
     1997 Outside Directors Stock Option Plan, the price is computed on the
     basis of the weighted average exercise price. As to the remaining shares
     under these plans, the price is based upon the average of the high and low
     prices of the Common Stock on March 10, 1998 as reported on the New York
     Stock Exchange. The 1997 Employee Stock Purchase Plan establishes a
     purchase price equal to 85% of the fair market value of the Company's
     Common Stock and, therefore, the price for purchase rights under this plan
     is based upon 85% of the average of the high and low prices of the Common
     Stock on March 10, 1998 as reported on the New York Stock Exchange.



                                       2
<PAGE>   3
                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT



Item 3. Incorporation of Documents by Reference


     American Residential Investment Trust, Inc. (the "Company") hereby
incorporates by reference in this registration statement the following
documents:


     (a) The Company's Prospectus filed pursuant to Rule 424(b) of the
Securities Act of 1933, as amended, containing audited financial statements for
the period from February 11, 1997 (commencement of operations) through June 30,
1997 as filed with the Securities and Exchange Commission (the "Commission") on
October 28, 1997 (registration number 333-33679).


     (b) All other reports filed pursuant to Section 13(a) or 15(d) of the
Securities Exchange Act of 1934, as amended (the "Exchange Act") since the end
of the fiscal year covered by the registrant document referred to in (a) above.


     (c) The description of the Company's Common Stock contained in its
Registration Statement filed with the Commission under the Exchange Act,
including any amendment or report filed for the purpose of updating such
description.


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


Item 4. Description of Securities


     The class of securities to be offered is registered under Section 12 of the
Exchange Act.


Item 5. Interests of Named Experts and Counsel


     Inapplicable.


Item 6. Indemnification of Directors and Officers


     As permitted by the Maryland General Corporation Law, the Company's
Articles of Amendment and Restatement obligates the Company to indemnify its
present and former directors and officers and to pay or reimburse reasonable
expenses for such individuals in advance of the final disposition of a
proceeding to the maximum extent permitted from time to time by Maryland law.
The Maryland General Corporation Law permits a corporation to indemnify its
present and former directors and officers, among others, against judgments,
penalties, fines,



                                       3
<PAGE>   4
settlements and reasonable expenses actually incurred by them in connection with
any proceeding to which they may be made a party by reason of their service in
those or other capacities, unless it is established that (a) the act or omission
of the director or officer was material to the matter giving rise to such
proceeding and was committed in bad faith or was the result of active and
deliberate dishonesty, (b) the director or officer actually received an improper
personal benefit in money, property or services, or (c) in the case of any
criminal proceeding, the director or officer had reasonable cause to believe
that the act or omission was unlawful. The Bylaws implement the provisions
relating to indemnification contained in the Company's Charter. Maryland law
permits the charter of a Maryland corporation to include a provision limiting
the liability of its directors and officers to the corporation and its
stockholders for money damages, except to the extent that (i) the person
actually received an improper benefit or profit in money, property or services,
or (ii) a judgment or other final adjudication is entered in a proceeding based
on a finding that the person's action, or failure to act, was the result of
active and deliberate dishonesty and was material to the cause of action
adjudicated in the proceeding. The Company's Charter contains a provision
providing for elimination of the liability of its directors or officers to the
Company or its stockholders for money damages to the maximum extent permitted by
Maryland law from time to time.


     The Company purchased and maintains officers' and directors' insurance for
the benefit of its officers and directors. The Company has entered into
indemnity agreements with each of its officers and directors pursuant to which
the Company indemnifies its officers and directors to the fullest extent allowed
by law.


Item 7. Exemption From Registration Claimed


     Inapplicable.


Item 8. Exhibits


     See Exhibit Index.


Item 9. Undertakings

     (a)  Rule 415 Offering

          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:

          (i)  To include any prospectus required by Section 10(a)(3) of the
               Securities Act;

          (ii) To reflect in the prospectus any facts or events arising after
               the effective date of the registration statement (or the most
               recent post-effective amendment thereof) which, individually or
               in the aggregate, represent a fundamental change in the
               information set forth in the registration statement;



                                       4
<PAGE>   5
          (iii)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;


provided, however, that paragraphs (a)(1)(i) and (a)(l)(ii) do not apply if the
registration statement is on Form S-3 or Form S-8, and the information required
to be included in a post-effective amendment by those paragraphs is contained in
periodic reports filed by the registrant pursuant to Section 13 or Section 15(d)
of the Exchange Act that are incorporated by reference in the registration
statement.


     (2)  That, for the purpose 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.


     (b)  Filing incorporating subsequent Exchange Act documents by reference


          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 (and, where applicable, each filing of an employee benefit plan's
annual report pursuant to 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.


     (h)  Request for acceleration of effective date or filing of registration
          statement on Form S-8


          Insofar as 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 the payment by the registrant of expenses
incurred or paid by a director, officer or controlling person of the registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, 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 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.



                                       5
<PAGE>   6
                                    SIGNATURE


     Pursuant to the requirements of the Securities Act, 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 San Diego, State of California, on March 13, 1998.

                                        American Residential Investment 
                                        Trust, Inc.
                                        By: /s/ Mark Conger
                                           --------------------------------
                                           Mark Conger
                                           Executive Vice President and 
                                           Chief Financial Officer



                                       6
<PAGE>   7
                        SIGNATURES AND POWER OF ATTORNEY



     The officers and directors of American Residential Investment Trust, Inc.
whose signatures appear below, hereby constitute and appoint Mark Conger,
Executive Vice President and Chief Financial Officer and Clay Strittmatter,
Secretary, and each of them, their true and lawful attorneys and agents, with
full power of substitution, each with power to act alone, to sign and execute on
behalf of the undersigned any amendment or amendments to this registration
statement on Form S-8, and each of the undersigned does hereby ratify and
confirm all that each of said attorney and agent, or their or his substitutes,
shall do or cause to be done by virtue hereof. Pursuant to the requirements of
the Securities Act, this registration statement has been signed by the following
persons in the capacities indicated on March 13, 1998.

<TABLE>
<CAPTION>
            Signature                                Title
-----------------------------------     -----------------------------------

<S>                                     <C>
/s/ John M. Robbins                     Chairman of the Board, Chief Executive
-----------------------------------       Officer and Director (Principal
John M. Robbins                           Executive Officer)


/s/ Jay M. Fuller                       President, Chief Operating Officer and
-----------------------------------       Director
Jay M. Fuller


/s/ Mark A. Conger                      Executive Vice President and Chief
-----------------------------------       Financial Officer (Principal Financial
Mark A. Conger                            and Accounting Officer)


/s/ H. James Brown, Ph.D.               Director
-----------------------------------
H. James Brown, Ph.D.


/s/ David E. De Leeuw                   Director
-----------------------------------
David E. De Leeuw


/s/ Ray McKewon                         Director
-----------------------------------
Ray McKewon


/s/ Richard T. Pratt, Ph.D              Director
-----------------------------------
Richard T. Pratt, Ph.D


/s/ Mark J. Riedy, Ph.D.                Director
-----------------------------------
Mark J. Riedy, Ph.D.
</TABLE>



                                       7
<PAGE>   8
                                  EXHIBIT INDEX

    4.1         Articles of Amendment and Restatement of the Company *
    4.2         Amended and Restated Bylaws of the Company**
    5           Opinion of Company Counsel
   23.1         Consent of Counsel ***
   23.2         Consent of KPMG Peat Marwick LLP
   24           Power of Attorney****


*    Incorporated by reference to Exhibit 3.1 to the Company's Form S-11 filed
     with the Securities and Exchange Commission on August 14, 1997.

**   Incorporated by reference to Exhibit 3.2 to the Company's Form S-11 filed
     with the Securities and Exchange Commission on August 14, 1997.

***  Included in Exhibit 5.

**** Included in the signature pages to this registration statement.
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 17525}]
{"company-data": {"conformed-name": "AMERICAN RESIDENTIAL INVESTMENT TRUST INC", "cik": "0001035744", "assigned-sic": "6798", "irs-number": "330741174", "state-of-incorporation": "MD", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-48005", "film-number": "98566161"}, "business-address": {"street1": "445 MARINE VIEW AVE SUITE 230", "street2": "STE 260", "city": "DEL MAR", "state": "CA", "zip": "92014", "phone": "6193505000"}, "mail-address": {"street1": "445 MARINE VIEW AVE SUITE 230", "city": "DEL MAR", "state": "CA", "zip": "92014"}}
1
                                                      Registration No. _________

                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM S-8

                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                   AMERICAN RESIDENTIAL INVESTMENT TRUST, INC.
             (Exact name of registrant as specified in its charter)

            Maryland                                    33-0741174
  (State or other jurisdiction              (I.R.S. employer identification no.)
of incorporation or organization)

                        445 Marine View Avenue, Suite 230
                            Del Mar, California 92014
               (Address of principal executive offices) (Zip code)

                   AMERICAN RESIDENTIAL INVESTMENT TRUST, INC.
                           1997 STOCK INCENTIVE PLAN,
                             1997 STOCK OPTION PLAN,
                       1997 EMPLOYEE STOCK PURCHASE PLAN,
                  AND 1997 OUTSIDE DIRECTORS STOCK OPTION PLAN
                            (Full title of the plan)

                          Clay Strittmatter (Secretary)
                   American Residential Investment Trust, Inc.
                        445 Marine View Avenue, Suite 230
                            Del Mar, California 92014
                     (Name and address of agent for service)

Telephone number, including area code, of agent for service: (619) 350-5008.
This registration statement shall hereafter become effective in accordance with
Rule 462 promulgated under the Securities Act of 1933, as amended (the
"Securities Act").

                                       1
2
--------------------------------------------------------------------------------------------------------------------------------
                                                 CALCULATION OF REGISTRATION FEE
--------------------------------------------------------------------------------------------------------------------------------
                                                                        Proposed              Proposed
                                                                        maximum                maximum
        Title of Securities to                 Amount to be        offering price per         aggregate            Amount of
         to be registered(1)                   registered               share(2)           offering price(2)    registration fee
----------------------------------------       ------------       ---------------------    ---------------      ----------------
1997 Stock Incentive Plan
Common Stock                                        315,200              $12.50              $ 3,940,000
Par Value $0.01

1997 Stock Option Plan
Common Stock                                        414,200              $15.00              $ 6,213,000
Par Value $0.01                                      60,600              $11.66              $   706,596

1997 Employee Stock Purchase Plan
Common Stock                                         20,000              $ 9.91              $   198,200
Par Value $0.01

1997 Outside Directors Stock Option Plan
Common Stock                                         30,000              $15.00              $   450,000
Par Value $0.01                                      30,000              $11.66              $   349,800

TOTALS                                              870,000                                  $11,857,596           $ 3,498.00
                                                                                                                 ---------------
----------------------
1    The securities to be registered include options and rights to acquire such
     Common Stock.

2    Estimated pursuant to Rule 457 solely for purposes of calculating the
     registration fee. As to shares subject to outstanding but unexercised
     options under the 1997 Stock Incentive Plan, 1997 Stock Option Plan and
     1997 Outside Directors Stock Option Plan, the price is computed on the
     basis of the weighted average exercise price. As to the remaining shares
     under these plans, the price is based upon the average of the high and low
     prices of the Common Stock on March 10, 1998 as reported on the New York
     Stock Exchange. The 1997 Employee Stock Purchase Plan establishes a
     purchase price equal to 85% of the fair market value of the Company's
     Common Stock and, therefore, the price for purchase rights under this plan
     is based upon 85% of the average of the high and low prices of the Common
     Stock on March 10, 1998 as reported on the New York Stock Exchange.

                                       2
3
                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference

     American Residential Investment Trust, Inc. (the "Company") hereby
incorporates by reference in this registration statement the following
documents:

     (a) The Company's Prospectus filed pursuant to Rule 424(b) of the
Securities Act of 1933, as amended, containing audited financial statements for
the period from February 11, 1997 (commencement of operations) through June 30,
1997 as filed with the Securities and Exchange Commission (the "Commission") on
October 28, 1997 (registration number 333-33679).

     (b) All other reports filed pursuant to Section 13(a) or 15(d) of the
Securities Exchange Act of 1934, as amended (the "Exchange Act") since the end
of the fiscal year covered by the registrant document referred to in (a) above.

     (c) The description of the Company's Common Stock contained in its
Registration Statement filed with the Commission under the Exchange Act,
including any amendment or report filed for the purpose of updating such
description.

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

Item 4. Description of Securities

     The class of securities to be offered is registered under Section 12 of the
Exchange Act.

Item 5. Interests of Named Experts and Counsel

     Inapplicable.

Item 6. Indemnification of Directors and Officers

     As permitted by the Maryland General Corporation Law, the Company's
Articles of Amendment and Restatement obligates the Company to indemnify its
present and former directors and officers and to pay or reimburse reasonable
expenses for such individuals in advance of the final disposition of a
proceeding to the maximum extent permitted from time to time by Maryland law.
The Maryland General Corporation Law permits a corporation to indemnify its
present and former directors and officers, among others, against judgments,
penalties, fines,

                                       3
4
settlements and reasonable expenses actually incurred by them in connection with
any proceeding to which they may be made a party by reason of their service in
those or other capacities, unless it is established that (a) the act or omission
of the director or officer was material to the matter giving rise to such
proceeding and was committed in bad faith or was the result of active and
deliberate dishonesty, (b) the director or officer actually received an improper
personal benefit in money, property or services, or (c) in the case of any
criminal proceeding, the director or officer had reasonable cause to believe
that the act or omission was unlawful. The Bylaws implement the provisions
relating to indemnification contained in the Company's Charter. Maryland law
permits the charter of a Maryland corporation to include a provision limiting
the liability of its directors and officers to the corporation and its
stockholders for money damages, except to the extent that (i) the person
actually received an improper benefit or profit in money, property or services,
or (ii) a judgment or other final adjudication is entered in a proceeding based
on a finding that the person's action, or failure to act, was the result of
active and deliberate dishonesty and was material to the cause of action
adjudicated in the proceeding. The Company's Charter contains a provision
providing for elimination of the liability of its directors or officers to the
Company or its stockholders for money damages to the maximum extent permitted by
Maryland law from time to time.

     The Company purchased and maintains officers' and directors' insurance for
the benefit of its officers and directors. The Company has entered into
indemnity agreements with each of its officers and directors pursuant to which
the Company indemnifies its officers and directors to the fullest extent allowed
by law.

Item 7. Exemption From Registration Claimed

     Inapplicable.

Item 8. Exhibits

     See Exhibit Index.

Item 9. Undertakings

     (a)  Rule 415 Offering

          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:

          (i)  To include any prospectus required by Section 10(a)(3) of the
               Securities Act;

          (ii) To reflect in the prospectus any facts or events arising after
               the effective date of the registration statement (or the most
               recent post-effective amendment thereof) which, individually or
               in the aggregate, represent a fundamental change in the
               information set forth in the registration statement;

                                       4
5
          (iii)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;

provided, however, that paragraphs (a)(1)(i) and (a)(l)(ii) do not apply if the
registration statement is on Form S-3 or Form S-8, and the information required
to be included in a post-effective amendment by those paragraphs is contained in
periodic reports filed by the registrant pursuant to Section 13 or Section 15(d)
of the Exchange Act that are incorporated by reference in the registration
statement.

     (2)  That, for the purpose 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.

     (b)  Filing incorporating subsequent Exchange Act documents by reference

          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 (and, where applicable, each filing of an employee benefit plan's
annual report pursuant to 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.

     (h)  Request for acceleration of effective date or filing of registration
          statement on Form S-8

          Insofar as 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 the payment by the registrant of expenses
incurred or paid by a director, officer or controlling person of the registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, 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 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.

                                       5
6
                                    SIGNATURE

     Pursuant to the requirements of the Securities Act, 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 San Diego, State of California, on March 13, 1998.

                                        American Residential Investment 
                                        Trust, Inc.
                                        By: /s/ Mark Conger
                                           --------------------------------
                                           Mark Conger
                                           Executive Vice President and 
                                           Chief Financial Officer

                                       6
7
                        SIGNATURES AND POWER OF ATTORNEY

     The officers and directors of American Residential Investment Trust, Inc.
whose signatures appear below, hereby constitute and appoint Mark Conger,
Executive Vice President and Chief Financial Officer and Clay Strittmatter,
Secretary, and each of them, their true and lawful attorneys and agents, with
full power of substitution, each with power to act alone, to sign and execute on
behalf of the undersigned any amendment or amendments to this registration
statement on Form S-8, and each of the undersigned does hereby ratify and
confirm all that each of said attorney and agent, or their or his substitutes,
shall do or cause to be done by virtue hereof. Pursuant to the requirements of
the Securities Act, this registration statement has been signed by the following
persons in the capacities indicated on March 13, 1998.
Signature                                Title
-----------------------------------     -----------------------------------
/s/ John M. Robbins                     Chairman of the Board, Chief Executive
-----------------------------------       Officer and Director (Principal
John M. Robbins                           Executive Officer)

/s/ Jay M. Fuller                       President, Chief Operating Officer and
-----------------------------------       Director
Jay M. Fuller

/s/ Mark A. Conger                      Executive Vice President and Chief
-----------------------------------       Financial Officer (Principal Financial
Mark A. Conger                            and Accounting Officer)

/s/ H. James Brown, Ph.D.               Director
-----------------------------------
H. James Brown, Ph.D.

/s/ David E. De Leeuw                   Director
-----------------------------------
David E. De Leeuw

/s/ Ray McKewon                         Director
-----------------------------------
Ray McKewon

/s/ Richard T. Pratt, Ph.D              Director
-----------------------------------
Richard T. Pratt, Ph.D

/s/ Mark J. Riedy, Ph.D.                Director
-----------------------------------
Mark J. Riedy, Ph.D.
7
8
                                  EXHIBIT INDEX

    4.1         Articles of Amendment and Restatement of the Company *
    4.2         Amended and Restated Bylaws of the Company**
    5           Opinion of Company Counsel
   23.1         Consent of Counsel ***
   23.2         Consent of KPMG Peat Marwick LLP
   24           Power of Attorney****

*    Incorporated by reference to Exhibit 3.1 to the Company's Form S-11 filed
     with the Securities and Exchange Commission on August 14, 1997.

**   Incorporated by reference to Exhibit 3.2 to the Company's Form S-11 filed
     with the Securities and Exchange Commission on August 14, 1997.

***  Included in Exhibit 5.

**** Included in the signature pages to this registration statement.