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

WOLF POPPER LLP
ROBERT M. KORNREICH
PAUL O. PARADIS
845 Third Avenue
New York, NY  10022
Telephone:  212/759-4600                   LAW OFFICES OF JAMES V.
                                             BASHIAN, P.C.
BERMAN, DeVALERIO & PEASE                  JAMES V. BASHIAN
GLEN DeVALERIO                             500 Fifth Avenue
One Liberty Square                         Suite 2700
Boston, MA  02109                          New York, NY  10110
Telephone:  617/542-8300                   Telephone:  212/921-4110

Attorneys for Plaintiff

                    SUPERIOR COURT OF THE STATE OF CALIFORNIA

                               COUNTY OF SAN DIEGO

JEANETTE ANDERSON, On Behalf of             )  Case No. 720391
Herself and All Others Similarly            )  
Situated,                                   )  CLASS ACTION 
                                            )  ------------ 
                    Plaintiff,              )
                                            )
     vs.                                    )
                                            )  JURY DEMAND
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 5, 1998
                                             MILBERG WEISS BERSHAD         
                                               HYNES & LERACH LLP          
                                             WILLIAM S. LERACH
                                             ALAN SCHULMAN
                                             DARREN J. ROBBINS

                                                 /s/ William S. Lerach
                                             ------------------------------
                                                   WILLIAM S. LERACH

                                             600 West Broadway, Suite 1800 
                                             San Diego, CA  92101          
                                             Telephone:  619/231-1058      
                                                                           
                                             WOLF POPPER LLP               
                                             ROBERT M. KORNREICH           
                                             PAUL O. PARADIS               
                                             845 Third Avenue              
                                             New York, NY  10022           
                                             Telephone:  212/759-4600      

                                             BERMAN, DeVALERIO & PEASE  
                                             GLEN DeVALERIO             
                                             One Liberty Square
                                             Boston, MA  02109
                                             Telephone:  617/542-8300   

                                             LAW OFFICES OF JAMES V.  
                                               BASHIAN, P.C.          
                                             JAMES V. BASHIAN         
                                             500 Fifth Avenue         
                                             Suite 2700               
                                             New York, NY  10110      
                                             Telephone:  212/921-4110 

                                             Attorneys for Plaintiff

                                     - 1 -


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

WOLF POPPER LLP
ROBERT M. KORNREICH
PAUL O. PARADIS
845 Third Avenue
New York, NY  10022
Telephone:  212/759-4600                   LAW OFFICES OF JAMES V.
                                             BASHIAN, P.C.
BERMAN, DeVALERIO & PEASE                  JAMES V. BASHIAN
GLEN DeVALERIO                             500 Fifth Avenue
One Liberty Square                         Suite 2700
Boston, MA  02109                          New York, NY  10110
Telephone:  617/542-8300                   Telephone:  212/921-4110

Attorneys for Plaintiff

                    SUPERIOR COURT OF THE STATE OF CALIFORNIA

                               COUNTY OF SAN DIEGO

JEANETTE ANDERSON, On Behalf of             )  Case No. 720391
Herself 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 her attorneys, alleges upon information and belief, except 
as to PARA 4 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 Corporation 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 Jeanette Anderson 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, 
manufacturers 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

                                     - 1 -


with its principal offices located at 2030 Dow Center, Midland, 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 Carlton 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 Khacharourians is a Director of Mycogen.

     13.  Defendant Nickolas D. Hein is the 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 a Vice President of Dow Agrosciences.

                                     - 2 -


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

     17.  The true names and capacities of defendants sued herein under 
California Code of Civil Procedures 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 and 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 her 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 defendants.

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

                                     - 3 -



          (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;

          (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 stockbrokers; and whether plaintiff and 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 refuse 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 interest 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.


                                    - 4 -


                               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 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 stand still 
agreement with Mycogen (the "Agreement"), Dow cannot acquire the remaining 
shares of Mycogen prior to February 1999.

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

     25.  The majority of the nine board members identified above are in 
irrevocable positions of conflict and cannot be expected to act in the best 
interest of Mycogen's minority stockholders in connection with this proposed 
transaction. They alone have the authority to vote to allow the amendment to 
the Agreement that is being sought by Dow and to thereby deprive Mycogen's 
minority shareholders of the true value of their Mycogen shares.

     26.  The sole 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.


                                    - 5 -


     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 
positioned to do so.

     28.  Dow has timed this transaction to capture Mycogen's future 
potential and is seeking to appropriate Mycogen's assets for itself without 
paying an adequate or fair price for the Company's remaining shares.

     29.  Amidst a backdrop of an improving financial position and increased 
prospects for growth, Dow announced its desire to acquire the remaining 
shares of Mycogen for $20.50 cash 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 Mycogen's minority common stockholders.

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


                                   - 6 -



          (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 in order to 
artificially depress 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.

     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 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

                                      - 7 -


               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 members of the Class.

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

                                      - 8 -


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 the 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 the other members of the Class;

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

     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;

     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

                                      - 9 -


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

DATED: May 5, 1998
                                             MILBERG WEISS BERSHAD
                                               HYNES & LERACH LLP
                                             WILLIAM S. LERACH
                                             ALAN SCHULMAN
                                             DARREN J. ROBBINS

                                                  /s/ William S. Lerach
                                             --------------------------------
                                                     WILLIAM S. LERACH

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

                                             WOLF POPPER LLP
                                             ROBERT M. KORNREICH
                                             PAUL O. PARADIS
                                             845 Third Avenue
                                             New York, NY 10022
                                             Telephone: 212/759-4600

                                             BERMAN, DeVALERIO & PEASE
                                             GLEN DeVALERIO
                                             One Liberty Square
                                             Boston, MA 02109
                                             Telephone: 617/542-8300

                                             LAW OFFICES OF JAMES V.
                                               BASHIAN, P.C.
                                             JAMES V. BASHIAN
                                             500 Fifth Avenue
                                             Suite 2700
                                             New York, NY 10110
                                             Telephone: 212/921-4110

                                             Attorneys for Plaintiff

                                      - 10 -