166 



talozzia guepini was reported by Bartlett and La Rue ( unpublished paper) 

 to consist of numerous distinct strains. Ascochyta chrysanthemi was 

 shown to consist of at least two distinct strains by Stevens and Hall (118). 

 Crabill (34) states that there are four distinctly different types^ of Phyl- 

 losticta pirina, and that Coniothyrium pirinum (34) is similarly composed 

 of distinct races. Burger (32) demonstrates a similar condition in the 

 genus Colletotrichum. Wiedemann (126) has published species of Peni- 

 cillium based on differences shown on culture media a procedure very 

 common in dealing with the bacteria. The wide-spread occurrence of 

 slightly but constantly differing varieties within the species of fungi is 

 apparent; also that two diametrically opposed methods of procedure are 

 in vogue to meet the situation. One method gives specific rank to each 

 elementary species, or race, or strain; the other restricts binomial desig- 

 nation to the larger groups (the collective species), recognizing that the 

 latter consist of numerous smaller groups the elementary species (or 

 races or strains). Lotsy (79) suggests that the terms "Linneon" defined 

 as "a total of individuals which resemble one another more than they do 

 any other individuals" and the term "Jordanon" for the elementary 

 species be employed. This suggestion, in that it recognizes the ele- 

 mentary species as properly in one category, and the group of elementary 

 species as belonging in a larger category, both subordinate to the genus, 

 is in accord with the general discussion of " Aspects of the Species Ques- 

 tion" (29) see particularly conclusions of Britton and remarks by Coul- 

 ter. The difficulties regarding elementary species that beset the taxono- 

 mist in dealing with the flowering plants are manifoldly increased when 

 the classification of the fungi imperfecti is in question. Thus in the 

 genus Septoria there are more than 1200 named species usually delimited 

 from each other by barely three or four characters, and these extremely 

 variable. Many other genera present conditions equally bewildering. 

 The result is that it is absolutely impossible, even with the type speci- 

 mens in hand (and they are usually unobtainable), to determine species 

 accurately. It is highly probable that many of the forms now listed as 

 species in the fungi imperfecti are either identical or merely biologic races 

 that is elementary species. To designate each elementary species 

 either in the fungi imperfecti or elsewhere by a binomial defeats the very 

 purpose of the name and renders it not only useless but cumbersome. 

 The conceptions of Lotsy and of Britton and Coulter as noted above, 

 seem particularly applicable here and indicate the advisability of using 

 a binomial to designate a group which shall comprise many elementary 



