PREFACE 



This treatise on fungi is intended as a reference and textbook. 

 Its content falls naturally into two portions. The first portion, 

 included in Volume I, is a consideration of the developmental 

 morphology and taxonomy of fungi and is basic to any compre- 

 hensive study of the fungi. The second portion, included in 

 Volume II, deals more specifically with the activities of fungi. 

 It must be borne in mind, however, that we have attempted 

 throughout the treatise to stress the need for more emphasis on 

 problems relating to fungus activities. 



The content of Volume II is concerned with metabolic and 

 reproductive activities, the modification of these activities by 

 environment, and the relationship of fungi to the welfare of 

 man. Consideration is also given to certain fungi for which 

 habitat is largely the basis of grouping. This volume may be 

 spoken of as physiological and ecological in its emphasis. It does 

 not purport, however, to constitute a well-rounded "physiology 

 and ecology of fungi" for the reason that experimental data are 

 still too meager to permit the preparation of such a textbook. 

 This explanation is made at the outset to guard the reader against 

 eventual disappointment. The need for a volume on the physi- 

 ology of fungi is keenly felt by all who seek such information in 

 textbooks on plant physiology, only to find that such books are 

 limited to consideration of the physiology of seed plants. 



Teachers may at first regard our departure from the tradi- 

 tional emphasis on taxonomy and classification as too radical to 

 put into practice. It should be remembered, however, that last- 

 ing impressions come from contact with living, functioning or- 

 ganisms. From experience we know that we remember with 

 facility where and under what circumstances we first encoun- 

 tered many different fungi in their natural habitats, and we re- 

 call how intent we became as we watched their development 

 and the changes which they induced. If, on the other hand, we 

 had been presented with an herbarium specimen, as is common 



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