vi PREFACE 



occasionally revised nnd amplified, has served essentially as a 

 text, and its presentation in book form has long been contem- 

 plated. The present volume represents the outcome of that 

 plan in so far as the lower fungi are concerned. It is, thus, 

 the natural outgrowth of the author's experience as a teacher, 

 and is in a large part a compilation based on the literature. No 

 claim is made that it embodies to any noteworthy extent knowl- 

 edge gained from personal research throughout the group. 



In even a cursory examination of the following pages the 

 reader will note that the treatment given the various families 

 and genera is not uniformly detailed. Some groups demand a 

 fuller discussion on account of their exceptional scientific interest ; 

 others have received it because of their outstanding economic 

 importance. Though the author has allowed himself consider- 

 able latitude in this regard, the effort has been made to stress 

 the material which contributes most to the usefulness of the 

 book. 



The plan of providing a separate bibliography at the close 

 of each chapter has been followed from the conviction that the 

 segregation of the references in this manner aids the student 

 in gaining a general knowledge of the literature. It makes 

 easier also the selection of papers for supplementary reading. 

 The bibliographies have been carefully prepared. Every 

 reference included serves a definite purpose, and is cited in the 

 text. If errors in these citations are discovered the author will 

 appreciate having them called to his attention. Though it is 

 not possible to state with assurance that all the literature pub- 

 lished prior to any given date has been incorporated, a deter- 

 mined attempt has been made to keep the manuscript up-to-date 

 during the process of its preparation. 



The omission of a glossary has been deliberate. Terms are 

 printed in boldface type at the points in the text at which they 

 are defined or their use definitely indicated. This explanatory 

 matter is available through the index. 



For pennission to reproduce illustrations from the works of 

 others the author is under deep obligation to a large number of 

 individuals and institutions in this country and abroad. Though 

 the hst is so long that detailed enumeration here seems inadvis- 

 able, full credit is given in the legends accompanying the figures. 

 A unifonn spirit of courtesy and generosity has been encountered 

 in every direction in this connection. 



