INTRODUCTION 3 



vitamin problem is common to many branches of science. Many other 

 problems investigated in fungus physiology are likewise common to other 

 related fields of study. 



In a similar way, a better understanding of certain related fields is 

 gained by knowledge of fungus physiology. The plant pathologist com- 

 monly finds it necessary to study the living parasitic fungus apart from 

 its host and must know something of the cultural methods and the spe- 

 cific nutritional requirements of the fungus at hand. The mycologist 

 and plant pathologist are faced with numerous unsolved problems which 

 must be investigated by physiological methods. One of the most chal- 

 lenging problems is the cultivation of certain fungi now classed as obligate 

 parasites on synthetic media of known composition. Until this is accom- 

 plished, the nutritional requirements of these fungi cannot be fully deter- 

 mined. Such knowledge would without doubt lead to a better under- 

 standing of parasitism and resistance. 



The taxonomic mycologist uses morphological characters almost exclu- 

 sively in his identification and classification studies, while the bacteriol- 

 ogist, being unable to use distinct morphological features to any great 

 extent, emphasizes the physiological characters in classifying bacteria. 

 Much more information is needed before it can be determined whether 

 any physiological characters are sufficiently valuable and uniform to be 

 used to supplement morphological characters in taxonomy of fungi. It 

 seems logical that such physiological differences between groups of fungi 

 do exist, and that the main problem lies in the discovery and recognition 

 of these characters and their application to taxonomy. On the other 

 hand, caution must be observed, for nutritional and environmental con- 

 ditions are known to affect, to a certain extent, some morphological 

 characters used in classification. 



The geneticist and the biochemist may find the fungi interesting and 

 suitable subjects for the study of their respective problems, while the 

 bacteriologist finds many points of similarity between the physiology of 

 the bacteria and that of the fungi. Industry has used many species of 

 fungi to its ovnx advantage for many decades. Yeasts were used long 

 before the physiology of the fungi became an organized study, but the 

 search for superior strains of yeast continues. The widespread use of 

 antibiotics has brought under laboratory study many species of fungi 

 which would otherwise have been ignored. This has created many new 

 problems of nutrition, especially with regard to large-scale cultivation of 

 these fungi. 



Thus, knowledge of the life activities of the fungi is important and useful 

 in many related fields of science, just as some knowledge of these related 

 fields is essential to an understanding of the fimgi. The study of fungup 

 physiology is justified as a separate field in which the basic or fundamental 



