8 G. L. McNew 



ious homologues and analogues in a class of active compounds with 

 representative cell constituents in vitro. By defining types of reac- 

 tions that molecules may be expected to enter into under specific con- 

 ditions, a suggestion may be revealed as to what the investigator 

 should be looking for in the living cell. This approach to the study 

 of fungicides by Dr. Burchfield and Miss Storrs at Boyce Thompson 

 Institute is revealing new analytical concepts. For example, one idea 

 is that there probably are microenvironments within each cell which 

 may very well determine whether the protein moiety of an enzyme 

 may react through the amino or sulfhydryl group with an alkylating 

 agent. 



It is only by prying into the living cell that the real answers to 

 growth-regulant processes of a molecule can be determined reliably. 

 Theories and reasoning from analogy are scarcely worth printing 

 until the treated living cell has been examined to verify the new 

 idea. A minor change in chemical structure in synthesizing a new 

 member of a class of regulants modifies so many attributes simul- 

 taneously that chances for error in reasoning are tremendous. Com- 

 pound this error by exposure to the multitudinous environmental 

 factors in the cell and one becomes most humble in recognition of 

 his own ignorance. 



To be blunt, there is no easy road open to determining the nature 

 of the relationship of chemical structure to activity. It is among one 

 of the more complicated mental exercises of modern science, and 

 more biologists should accept the situation in humility and determi- 

 nation to obtain many divergent lines of evidence before being too 

 positive in any one theory. 



THE GREAT NEED FOR BETTER PLANT REGULATION 



The opportunities to serve men better through science probably 

 are greater in this field than in almost any area of scientific endeavor. 

 VVe work to improve the material comforts of man, stabilize his so- 

 ciety, and permit the continued growth and development of his econ- 

 omy in a world where the physical resources for plant culture are 

 drastically limiting. The things that can be done, and will be done, 

 in this area are tremendous. Is there any harm to dream of what we 

 may do in the years ahead? 



If we could free certain valuable crop plants from their depend- 

 ence upon rigid photoperiod requirements, the barrier of geographi- 

 cal latitude might be broken so many unused or poorly used areas 

 could be sown to much needed crops. Furthermore, there are many 

 areas where two seed crops might be grown in place of one each year 



