VI 



PREFACE 



was that, as all older mycologists appreciate, much which was 

 once regarded as truth has been and is being supplanted. To un- 

 learn seems no less difficult a task than to learn. It must be re- 

 membered, too, that it is a prodigious task to become conversant 

 with new truths, which must be sifted from voluminous myco- 

 logical literature. 



Information about a particular fungus is conveyed most satis- 

 factorily if one is able to orient it as to its structure and its rela- 

 tionship with other species. This orientation is best achieved 

 by using its name under standingly. For each order and family, 

 the barest essentials of morphology and development are given. 

 So far as possible, species of economic importance have been 

 chosen for this purpose. 



Certain families have been omitted, mainly because they are 

 so little known. This deficiency may incite adverse criticism, 

 some of which is conceded to have real merit. A conscious effort 

 has been made to de-emphasize phylogeny, so that the teacher 

 with definite convictions on relationships among fungi will not 

 be handicapped or inhibited by our opinions, expressed or im- 

 plied. The value of present-day interpretations of phylogeny 

 among fungi, in our opinion, still remains largely open to 

 question. 



In some instances the most acceptable binomials have not been 

 used; instead we have used the name employed by the writer of 

 the report cited. This practice should not create any serious 

 difficulties for the person interested in synonomy. Except in a 

 few instances, we have not cited the authoritv^ for the binomials 

 employed, for two reasons: (1) the correct authority can be 

 had from Saccardo's Sylloge Fiingonim or from some mono- 

 graph, and (2) valuable space is saved throughout by these 

 omissions. 



We have arbitrarily chosen to give no consideration to lichens. 

 Mycologists may eventually agree that they should be dispersed 

 among the Eurotiales, Sphaeriales, Hypocreales, Hysteriales, in- 

 operculate Discomycetes, and other groups. It seems to us that, 

 if and when this is done, it will be the result of overemphasis of 

 the morphology of reproductive structures and of underemphasis 

 of a very specialized structure, the lichen thallus. It would 

 appear that the structure of the thallus and its correlated, sym- 



