MILBERG WEISS BERSHAD
  HYNES & LERACH LLP
WILLIAM S. LERACH (68581)
ALAN SCHULMAN (128661)
DARREN J. ROBBINS (168593)
600 West Broadway, Suite 1800
San Diego, CA 92101
Telephone:  619/231-1058

ABBEY, GARDY & SQUITIERI, LLP
MARK C. GARDY
JAMES S. NOTIS
212 East 39th Street
New York, NY 10016
Telephone:  212/889-3700

Attorneys for Plaintiff

                   SUPERIOR COURT OF THE STATE OF CALIFORNIA
                             COUNTY OF SAN DIEGO

LESLIE SUSSER, On Behalf of Himself   )  Case No.
and All Others Similarly Situated,    )
                                      )  CLASS ACTION
                    Plaintiff,        )
                                      )  COMPLAINT BASED UPON UNFAIR
     vs.                              )  BUSINESS PRACTICES, SELF
                                      )  DEALING AND BREACH OF
MYCOGEN CORPORATION, J. PEDRO         )  FIDUCIARY DUTY
REINHARD, CARLTON J. EIBL, JOHN L.    )
HAGAMAN, JOSEPH P. SULLIVAN, ROY M.   )
BARBEE, GEORGE KHACHATOURIANS,        )
NICKOLAS D. HEIN, G. WILLIAM          )
TOLBERT, LOUIS W. PRIBILA, DOW        )
CHEMICAL COMPANY and DOES 1-25,       )
inclusive,                            )
                                      )
                    Defendants.       )  Plaintiff Demands A
                                      )  Trial By Jury
- ------------------------------------- )  -------------------




     Plaintiff. by his name attorneys, alleges upon information and belief, 
except as to PARA4 which plaintiff alleges upon knowledge, as follows:

                          JURISDICTION AND VENUE

     1. This Court has jurisdiction over all causes of action asserted herein 
pursuant to the California Constitution, Article XL, Section 10, because this 
case is a cause not given by statute to other trial courts.

     2. This court has jurisdiction over Mycogen because this defendant is a 
California corporation with its principal place of business at 5501 Oberlin 
Drive, San Diego, California.

     3. Venue is proper in this Court because the conduct at issue took place 
and had an effect in this County and defendants made misrepresentations which 
had an effect in this County.

                                  PARTIES

     4. Plaintiff Leslie Susser is a stockholder of defendant Mycogen 
Corporation ("Mycogen" or the "Company").

     5. Defendant Mycogen is a corporation duly organized and existing under 
the laws of the state of California, with its principal offices located at 
5501 Oberlin Drive, San Diego, California 92121. Mycogen develops, 
manufactures and markets biopesticides as alternatives to chemical pesticides 
to control a variety of insects, weeds and parasitic worms. As of April 7, 
1998, there were over 36 million shares of Mycogen common stock outstanding.

     6. Defendant Dow Chemical Company ("Dow") is a corporation duly 
organized and existing under the laws of the State of Delaware with its 
principal offices located at 2030 Dow Center, Midland,



                                  1


Michigan 48674.  Dow is the fifth largest chemical company in the world, with 
annual sales of more than $20 billion.  Dow manufactures and supplies 
chemicals, plastics, energy, agricultural products, consumer goods and 
environmental services.  Through its wholly-owned subsidiary, Dow 
Agrosciences, LLC ("Dow Agrosciences"), Dow owns or controls shares 
representing approximately 69 percent of the outstanding common stock of 
Mycogen.

     7.  Defendant J. Pedro Reinhard is a Director of Mycogen and the Chief 
Financial Officer and Executive Vice President of Dow Agrosciences.

     8.  Defendant Charles J. Eibl is the President of Mycogen and a member 
of its Board of Directors.

     9.  Defendant John L. Hagaman is a Director of Mycogen and the President 
of Dow Agrosciences.

     10.  Defendant Joseph P. Sullivan is a Director of Mycogen.

     11.  Defendant Roy M. Barbee is a Director of Mycogen.

     12.  Defendant George Khachatourians is a Director of Mycogen.

     13.  Defendant Nickolas D. Hein is a Chairman of Mycogen's Board of 
Directors and a Vice President of "Global Growth" for Dow Agrosciences.

     14.  Defendant G. William Tolbert is a Director of Mycogen and a "Global 
Business Development Director" for Dow Agrosciences.

     15.  Defendant Louis W. Pribila is a Director of Mycogen and the 
Secretary, General Counsel and Vice President of Dow Agrosciences.

     16.  The Defendants named in PARAs 7 through 15 are sometimes 
collectively referred to herein as the "Individual Defendants."



                                      2



     17.  The true names and capacities of defendants sued herein under 
California Code of Civil Procedure Section 474 as Does 1 through 25, 
inclusive, are presently not known to plaintiff, who therefore sues these 
defendants by such fictitious names.  Plaintiff will seek to amend this 
Complaint and include these Doe defendants' true names and capacities when 
they are ascertained.  Each of the fictitiously named defendants is 
responsible in some manner for the conduct alleged herein and for the 
injuries suffered by the Class.

     18.  The Individual Defendants as officers and/or directors of Mycogen 
have a fiduciary relationship and responsibility to plaintiff and the other 
common public stockholders of Mycogen and owe to plaintiff the other class 
members the highest obligations of good faith, loyalty, fair dealing, due care
and candor.

                         CLASS ACTION ALLEGATIONS

     19.  Plaintiff brings this action pursuant to Section 382 of the 
California Code of Civil Procedure on his own behalf and as a class action on 
behalf of all common stockholders of Mycogen, or their successors in 
interest, who are being and will be harmed by defendants' actions described 
below (the "Class").  Excluded from the Class are defendants herein and any 
person, firm, trust, corporation, or other entity related to or affiliated 
with any of the defendants.

     20.  This action is properly maintainable as a class action because:

          (a)  The Class is so numerous that joinder of all members is 
impracticable.  There are hundreds of Mycogen stockholders of record who are 
located throughout the United States; 


                                  3
            



          (b)  There are questions of law and fact which are common to the 
Class, including:  whether the defendants have engaged or are continuing to 
act in a manner calculated to benefit themselves at the expense of Mycogen's 
minority stockholders;  and whether plaintiff and the other members of the 
Class would be irreparably damaged if the defendants are not enjoined in the 
manner described below;

          (c)  The defendants have acted or refused to act on grounds 
generally applicable to the Class, thereby making appropriate final 
injunctive relief with respect to the Class as a whole;

          (d)  Plaintiff is committed to prosecuting this action and has 
retained competent counsel experienced in litigation of this nature.  The 
claims of plaintiff are typical of the claims of the other members of the 
Class and plaintiff has the same interests as the other members of the Class. 
Accordingly, plaintiff is an adequate representative of the Class and will 
fairly and adequately protect the interests of the Class; and

          (e)  Plaintiff anticipates that there will be no difficulty in the 
management of this litigation as a class action.

     21.  For the reasons stated herein, a class action is superior to other 
available methods for the fair and efficient adjudication of this controversy.

                           CLAIM FOR RELIEF

     22.  Mycogen is a California corporation that develops, manufactures and 
markets biopesticides as alternatives to chemical pesticides to control a 
variety of insects, weeds and parasitic worms.  The Company's products are 
based on natural agents that are 

                                 4




compatible with the environment and are developed through genetic engineering 
technology and innovative formulations.
  
     23. Dow currently owns or controls approximately 69 percent of the 
outstanding common stock of Mycogen. Under the terms of a prior agreement 
with Mycogen (the "Agreement"), Dow cannot acquire the remaining shares of 
Mycogen before February 1999.

     24. After the close of trading on April 30, 1998, it was reported that 
Dow, through Dow Argosciences, requested an amendment to the Agreement to 
permit it to begin discussions regarding the acquisition of the remaining 
shares of Mycogen common stock it does not already own for $20.50 per share 
in cash.

     25. As set forth above, Mycogen has 9 board members whose loyalties are,
at best, divided in the instant transaction and cannot be expected to act 
in the best interest of Mycogen's minority stockholders.

     26. The purpose of the proposed acquisition is to enable Dow to acquire 
the shares of Mycogen it does not already own, as well as Mycogen's valuable 
assets, for Dow's own benefit at the expense of Mycogen's minority 
stockholders.

     27. The proposed acquisition comes at a time when Mycogen has performed 
well and Dow expects it will continue to perform well because it is already 
well positioned to do so.

     28. Dow has timed this transaction to capture Mycogen's future potential 
and use it to its own ends without paying an adequate or fair price for the 
Company's remaining shares.

     29. Amidst this backdrop of positive and improving financial position 
and increased prospects for growth, Dow announced its desire to acquire the 
remaining shares of Mycogen for $20.50 cash



                                  5


per share. The offer made by Dow represents no premium over the current price 
of Mycogen common stock. In fact, prior to Dow's announcement on April 30, 
1998, the price of Mycogen common stock closed at $20.625 per share -- higher 
than the price offered by Dow in the proposed acquisition.

     30. The Individual Defendants and Dow are in a position of control and 
power over Mycogen's stockholders and have access to internal financial 
information about Mycogen, its true value, expected increase in true value 
and the benefits to Dow of 100 percent ownership of Mycogen to which 
plaintiff and the Class members are not privy. Defendants are using their 
positions of power and control to benefit Dow in this transaction, to the 
detriment of the Mycogen common stockholders.

     31. In proposing the aquisition, Dow and the Individual Defendants have 
committed or threatened to commit the following acts to the detriment and 
disadvantage of Mycogen minority stockholders:

         (a) They have undervalued Mycogen's common stock by ignoring the full
value of its assets and future prospects. The proposed acquisition 
consideration does not reflect the value of Mycogen's valuable assets; and

         (b) They timed the announcement of the proposed buyout to place an 
artificial lid on the market price of Mycogen's common stock to justify a 
price that is unfair to Mycogen's minority stockholders.
 
     32. The Individual Defendants have clear and material conflicts of 
interest and are acting to better the interests of Dow and themselves at the 
expense of Mycogen's minority stockholders.



                                  6


     33.  In light of the foregoing, the Individual Defendants must, as their 
fiduciary obligations require:

     -    undertake an appropriate evaluation of Mycogen's worth as an 
          acquisition candidate;

     -    act independently so that the interests of Mycogen's minority 
          stockholders will be protected, including but not limited to the 
          retention of independent advisors and the appointment of a Special 
          Committee of some or all of the members of the Mycogen's board to 
          consider the Dow offer and negotiate with Dow on behalf of 
          Mycogen's minority stockholders;

     -    adequately ensure that no conflicts of interest exist between 
          defendants' own interests and their fiduciary obligation to 
          maximize stockholder value or, if such conflicts exist, to ensure 
          that all conflicts be resolved in the best interests of Mycogen's 
          minority stockholders; and

     -    if an acquisition transaction is to go forward, require that it be 
          approved by a majority of Mycogen's minority stockholders.

     34.  As a result of the defendants' failure to take such steps to date, 
plaintiff and the other members of the Class have been and will be damaged in 
that they have not and will not receive their proportionate share of the 
value of the Company's assets and business, and have been and will be 
prevented from obtaining a fair price for their common stock.

     35.  Defendants, in failing to disclose the material non-public 
information in their possession as to the value of Mycogen's assets, the full 
extent of the future earnings potential of Mycogen and its expected increase 
in profitability, are engaging in self-dealing, are not acting in good faith 
toward plaintiff and the other members of the Class, and have breached and 
are breaching their fiduciary duties to the member of the Class.

     36.  As a result of the defendants' unlawful actions, plaintiff and the 
other members of the Class will be irreparably


                                       7 



harmed in that they will not receive their fair portion of the value of 
Mycogen's assets and business and will be prevented from obtaining the real 
value of their equity ownership of the Company.  Unless the proposed 
acquisition is enjoined by the Court, defendants will continue to breach 
their fiduciary duties owed to plaintiff and the members of the Class, will 
not engage in arm's-length negotiations on the acquisition terms, and will 
not supply to Mycogen's minority stockholders sufficient information to 
enable them to cast informed votes on the proposed acquisition and may 
consummate the proposed acquisition, all to the irreparable harm of the 
members of the Class.

     37.  Plaintiff and other members of the Class have no adequate remedy at 
law.
                             PRAYER FOR RELIEF

     WHEREFORE, plaintiff prays for judgment and relief as follows:

     1.  Ordering that this action may be maintained as a class action and 
certifying plaintiff as the Class representative;

     2.  Declaring that defendants have breached their fiduciary and other 
duties to plaintiff and other members of the Class;

     3.  Entering an order requiring defendants to take the steps set forth 
hereinabove;

     4.  Preliminarily and permanently enjoining the defendants and their 
counsel, agents, employees and all persons acting under, in concert with, or 
for them, from proceeding with, consummating or closing the proposed 
transaction;

     5.  In the event the proposed acquisition is consummated, rescinding it 
and setting it aside;


                                      8


     6.  Awarding compensatory damages against defendants individually and 
severally in an amount to be determined at trial, together with prejudgment 
interest at the maximum rate allowable by law;

     7.  Awarding costs and disbursements, including plaintiff's counsel's 
fees and experts' fees; and

     8.  Granting such other and further relief as to the Court may seem 
just and proper.

DATED:  May 1, 1998                  MILBERG WEISS BERSHAD
                                      HYNES & LERACH LLP
                                     WILLIAM S. LERACH
                                     ALAN SCHULMAN
                                     DARREN J. ROBBINS


                                         /s/ Alan Schulman
                                     -----------------------------------
                                             ALAN SCHULMAN

                                     600 West Broadway, Suite 1800
                                     San Diego, CA 92101
                                     Telephone: 619/231-1058

                                     ABBEY, GARDY & SQUITIERI, LLP
                                     MARK C. GARDY
                                     JAMES S. NOTIS
                                     212 East 39th Street
                                     New York, NY 10016
                                     Telephone: 212/889-3700

                                     Attorneys for Plaintiff



                                      9 



MILBERG WEISS BERSHAD
  HYNES & LERACH LLP
WILLIAM S. LERACH (68581)
ALAN SCHULMAN (128661)
DARREN J. ROBBINS (168593)
600 West Broadway, Suite 1800
San Diego, CA 92101
Telephone:  619/231-1058

ABBEY, GARDY & SQUITIERI, LLP
MARK C. GARDY
JAMES S. NOTIS
212 East 39th Street
New York, NY 10016
Telephone:  212/889-3700

Attorneys for Plaintiff

                   SUPERIOR COURT OF THE STATE OF CALIFORNIA
                             COUNTY OF SAN DIEGO



                                   

LESLIE SUSSER, On Behalf of Himself   )  Case No. 720255
and All Others Similarly Situated,    )
                                      )  CLASS ACTION
                    Plaintiff,        )
                                      )  JURY DEMAND
     vs.                              )
                                      )
MYCOGEN CORPORATION, J. PEDRO         )
REINHARD, CARLTON J. EIBL, JOHN L.    )
HAGAMAN, JOSEPH P. SULLIVAN, ROY M.   )
BARBEE, GEORGE KHACHATOURIANS,        )
NICKOLAS D. HEIN, G. WILLIAM          )
TOLBERT, LOUIS W. PRIBILA, DOW        )
CHEMICAL COMPANY and DOES 1-25,       )
inclusive.                            )
                                      )
                    Defendants.       )
                                      )
- ------------------------------------- )





     Plaintiff demands a trial by jury.

DATED:  May 1, 1998                  MILBERG WEISS BERSHAD
                                      HYNES & LERACH LLP
                                     WILLIAM S. LERACH
                                     ALAN SCHULMAN
                                     DARREN J. ROBBINS


                                         /s/ Alan Schulman
                                     -----------------------------------
                                             ALAN SCHULMAN

                                     600 West Broadway, Suite 1800
                                     San Diego, CA 92101
                                     Telephone: 619/231-1058

                                     ABBEY, GARDY & SQUITIERI, LLP
                                     MARK C. GARDY
                                     JAMES S. NOTIS
                                     212 East 39th Street
                                     New York, NY 10016
                                     Telephone: 212/889-3700

                                     Attorneys for Plaintiff


                                       1