572 WESTON 



velopment groups of the Quartermaster Corps and other agencies to the chal- 

 lenge of the losses and problems brought up by tropical deterioration. In still 

 other instances the impetus was given by the effectiveness of new tools which 

 could be applied to investigation, as, for example, the use of radiation in 

 inducing mutations and other significant responses on the part of fungi or the 

 use of materials tagged with radioactive materials such as C^* as a key to 

 unlock some hitherto baffling phases of metabolism. x\lso, the application of 

 microdissection apparatus of increasing precision to ever more delicate re- 

 search procedures, or the use of the "smear and squash" cytological techniques 

 and of phase microscopy for the effective interpretation of nuclear and other 

 minute features led to notable advances, while electron microscopy applied 

 to intricate submicroscopic structure in the fungi as in other groups revealed 

 features hitherto unsuspected and of great significance. Similarly, the applica- 

 tion of time-lapse motion-picture photography to the timing and careful study 

 of developmental sequences of fundamental importance has instigated signifi- 

 cant advances. 



The progress has been so impressive and the quality and quantity of the 

 significant results so notable that in the present survey of the advances and 

 the outstanding achievements with which Mycology has contributed to Botany 

 during the past half century, the problem is one of selecting the examples 

 most fittingly representative, most justly evaluative, and most suitable for 

 presentation here within the limits of time imposed by the program. Hence, 

 in the following examples, if there is neglect of the areas you feel are more 

 significant, attribute this to the limitations in time inherent in the program 

 and the limitations in discrimination inherent in the speaker. 



As examples of the steady progress shown by Mycology in its long-estab- 

 lished areas, the following are representative. Taxonomy has made helpful 

 progress, not only through the employment of the long-established means such 

 as structural and reproductive features, but also through the utilization of 

 more recent approaches such as the chromosome numbers in the wild species 

 and crosses of Allomyces, the nuclear behavior in certain Mucorales and other 

 Phycomycetes, the nature and activity of the flagellate motile apparatus in 

 certain of the water molds, or the biochemical differences manifesting them- 

 selves in the pathogenicity of certain rusts of grain, in the metabolism of cer- 

 tain molds, and in the composition of the wall in certain aquatic fungi. The 

 structure, development, and relationships of groups found in certain habitats 

 previously only meagerly explored have been greatly extended and clarified 

 by the work of Von Minden, Coker, Couch, Sparrow, Karling, and others on 

 the submersed Phycomycetes; of Ingold, Ranzoni, and others on the Imperfect 

 Fungi of fresh-water habitats, as well as by the work of Petersen, Sutherland, 

 Linder, Barghoorn, Sparrow, and others on the unexpectedly diverse and 

 fascinating fungus flora of the sea. Of ecological significance has been the 

 extension in our understanding of the relation of the activities of the insect 



