PREFACE TO THE FIRST EDITION 



The bacteriologist is continually confronted with molds, yeasts, 

 and Actinomycetes, no matter what may be the particular field of 

 application of the science in which he is engaged. Many of these are 

 but contaminants, as Thom says, "noxious weeds" which plague him 

 by overgrowing his cultures of bacteria. But an ever-increasing 

 number of fungi are found to be causes of disease processes in man. 

 and animals, while in the chemical transformations of the soil and 

 spoilage of foods and other organic products of industry they are of 

 equal importance with the bacteria. The industrial uses of these 

 microorganisms have been known to a limited extent for some time, 

 but promise to undergo extensive development in the near future. 

 These fungi cannot, then, be ignored by the bacteriologist. 



The lower fungi are of interest, however, not alone because of 

 their practical importance. Very significant and interesting facts 

 are being discovered concerning their complicated life-cycles, par- 

 ticularly with regard to the behavior of the nuclei, and their sexual 

 relations, which will have an important bearing upon problems of 

 variation and evolution in this group. Since it is becoming daily 

 more clearly evident that at least some of the bacteria belong to 

 the fungi, and there is a well-defined movement to trace similar 

 cycles and relationships in the bacteria, it behooves the bacteriologist 

 to make himself acquainted with at least the essentials of this newer 

 knowledge. 



This book will, it is hoped, help fill the gap existing between the 

 brief and inadequate discussions of the fungi found in current 

 textbooks of bacteriology and the extensive monographs and tech- 

 nical articles which treat of particular groups. The latter are too 

 extensive to be easily used, too technical to be easily understood by 

 the student of bacteriology who generally has no foundation in 

 mycology. 



In this work I have tried to present sufficient information about 

 fungi in general, and about those forms of importance to the bacteri- 

 ologist in particular, so that the student will be prepared to use the 

 more technical literature; to present such description and keys that 

 will enable him with confidence to identify some of the commoner 



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