206 MEDICAL MYCOLOGY 



Undoubtedly many of the species so far described are primarily sapro- 

 phytes and are present in the lesions as secondary invaders. This may ac- 

 count for the relatively large numbers of organisms which have not been 

 reported more than once. On the other hand, there seem to be rapidly ac- 

 cumulating indications that some of the organisms of this group are primarily 

 parasitic, or at least so profoundly modify other factors in the production of 

 disease that they should be considered seriously in the study of the disease. 

 It is to be hoped that with clearer ideas of morphology and physiology of these 

 organisms and a recognition of the ability of many different species to occur in 

 essentially the same clinical entity, we may have tools which will aid us in a 

 more accurate delimitation of species. No really stable clinical differentia- 

 tions, sound animal experimentation, or rational therapeusis can be built up 

 until we have broader and more thorough studies of the many organisms in- 

 volved. In the folloAving systematic discussion, I have attempted to refer 

 organisms to the various genera on the basis of their published descriptions, 

 realizing thoroughly that only a portion of the characters are given, I have 

 also very largely refrained from reducing species to synonymy, since I feel 

 that the burden of proof rests with him who would reduce species rather than 

 with the describer of new species. It is, therefore, quite probable that several 

 species here recognized will eventually be shown to be synonymous with other 

 species, but I feel that at the present time there are few studies sufficiently 

 extensive and thorough upon which to base such action. 



Key to Genera of Eremascaceae Imperfecta^ 



Mycelium breaking up into arthrospores, i.e., cells of the filaments cyclindrie or nearly so 

 after separation. 

 Colony cerebriform, villous, irregular, growth slow, little or no growth on liquid media, 



arthrospores not very abundant. Proteomyces. 



Colony membranous, folded, dull, usually grayish white. 



True mycelium not fragile before disarticulation of arthrospores, no blastospores ; 

 thick pellicle on liquid media, sugars not fermented. 

 Gelatin liquefied. Geotrichum. 



Gelatin not liquefied. Mycoderma. 



Pseudomycelium fragile, conidia and transitional forms between blastospores and 

 arthrospores present. 

 Gelatin not liquefied, no pellicle on liquid media, although occasionally a partial 

 ring formed. 

 Blastospores verticillate, sugars fermented. Candida (Geotrichaides). 



Blastospores single, sugars not fermented. Schizoblastosporion. 



Gelatin liquefied, chalky- white to yellowish pellicle on liquid media, cells long 

 fusiform or apiculate, sugars fermented. Pseudomycoderma. 



Arthrospores not produced, blastospores abundant and characteristic, colony creamy, yellowish 

 white, shining. 



Pseudomycelium little branched, blastospores not in verticils nor in regular pairs at the 

 ends of pseudomycelial cells; cells ellipsoid. 

 Gelatin not liquefied, no pellicle, although rings are sometimes produced. 

 Sugars not fermented. Parendomyces. 



Sugars fermented. Castellania. 



