CHAPTER XIII 

 ISACCHAROMYCETACEAE IMPEREECTAE 



111 thiti group of organisms, whose perfect stages are unknown, we have 

 practically the same situation as we found in the Eremascaceae Imperfectae. 

 In this group Cryptococcus occupies a position corresponding to that which 

 Monilia occupied in the other. Fortunately for our purposes, fewer genus names 

 have been proposed and of the small genera segregated, few have any relation- 

 ship to disease. We have very many poorly described species, especially those 

 reported to have some relationship to tumors, during the period when yeasts 

 were regarded as etiologic agents in the production of hypei-plasias. Some 

 may have been based on artefacts (especially those which were not culti- 

 vated), and the others were perhaps contaminants, probably unimportant in 

 relation to disease, but nevertheless apparently definite species, although 

 poorly described. 



Key to Genera 



Cells with vestigial copulation canals. Asporomyces. 



Cells without traces of copulation. 



Cells small, often flask-shaped, not easily isolated on ordinary media (see p. 358). 



Malassezia. 



Cells larger, cultivable on ordinary media. 



Cells apiculate to citriform, producing a small ring with small, moist, thin, floating 

 islets which may coalesce to form a very fragile moist pellicle, easily sink- 

 ing, gelatin liquefied, fermentation present. Pseudosaccharomyces. 

 Cells rounded, not apiculate. 



Cells producing abundant microblastospores, producing slight ring, gelatin lique- 

 fied, fermentation present, Microblastosporion. 

 Cells multiplying by ordinary sprouting. 



Cells thick-walled, often embedded in a gelatinous matrix, pellicle thick, 

 formed by the confluence of slimy floating islets when present, sedi- 

 ment slimy, gelatin not liquefied, or liquefied very slowly. 

 No fermentation. Cryptococcus. 



Fermentation present. Atelosaccharomyces. 



Cells thin-v,-alled, not embedded in a gelatinous matrix, pellicle commonly 

 present, gelatin liquefied. 

 Young cells with oil globules, pellicle slimy, sugars fermented. 



Eutorula. 

 Young cells without oil globules, pellicle dry, fragile, with slight folding, 

 little or no fermentation of sugars, colonies usually pink or 

 reddish. Torulopsis. 



325 



