TAXONOMY 43 



bacteria, many species, and some strains of nearly all species, will 

 "stay put" almost indefinitely in artificial cultures. Strains recently 

 isolated from their natural habitat are likely to be very stable, and 

 if old laboratory strains ''go pleomorphic," they can usually be read- 

 ily replaced. Spontaneous variations are of course of importance in 

 explaining the occurrence of new races or physiological types of 

 pathogenic fungi, especially in the plant parasites, and the possibility 

 of developing new industrial yeasts and molds by induced mutations 

 or by hybridization is an attractive field for investigation. But the 

 phenomena of variation in fungi are probably most important from 

 the standpoint of classification and nomenclature. Some of the 

 variants which have been observed differ so much from the parent 

 culture that one might be justified in calling them new species. And 

 some of the variants, particularly those described by Emmons on hi? 

 studies of dermatophytes, are apparently identical with species al- 

 ready known in nature. 



Taxonomy. Throughout nature individuals exist in infinite vari- 

 ety, and when we group them into species we draw artificial lines 

 which do not actually exist. This has led, throughout the history of 

 biology, to a conflict between the "splitters" who would make a new 

 species of every new individual, and the "lumpers" who recognize 

 only the grossest of differences. "The 'lumper' is the horror of the 

 'splitter,' the 'splitter' is anathema to the 'lumper'; both are the 

 source of genuine grief and much hardship to conscientious men, who 

 are possessors of normally constituted minds and truly scientific 

 habits." t Conscientious men with normal minds and scientific habits 

 will recognize the modal types about which.individuals fluctuate, and 

 designate these as species. They will recognize the normal limits of 

 variation within these species. 



Unfortunately in the study of the lower fungi we have suffered 

 from a plethora of splitters and a dearth of lumpers. This is due, in 

 part, to the failure of most workers to take into account the frequent 

 occurrence of slight and often transient variations. Thus we have 

 in the literature of medical mycology probably two or three hundred 

 species names and combinations wdiich differ mainly in slight varia- 

 tions in form, color, or texture of the colonies — characters which are 

 almost never constant. Similar conditions obtain in many other 

 genera of the lower fungi. As our investigations of variation con- 

 tinue, many of these species will necessarily be reduced to synonymy. 



t W. J. Holland in The Moth Book. 



