112 



THE FUNGI IMPERFECT! AND THE ASCOMYCETES 



been named variously Saccharomyces niger, Torula nigra, Schizo- 

 saccharomyces niger, and Monilia nigra. They have been isolated 

 from a variety of substrates, mostly dairy products. Organisms of 

 this type have been found to produce outbreaks of black spots in 

 Emmenthaler cheese. An apparently identical organism as a cause 

 of spoilage of raw sugar has been reported. Similar forms have been 

 isolated from soil, from air, from commercial yeast cakes, from in- 

 sects, and from certain pathological lesions of man where, however, 

 they may not be in all cases the causative agent of the disease. 



Fig. 64. "Monilia nigra." 



There has been some question regarding the identity of the various 

 forms described and their proper classification. Henrici examined 

 a dozen or more strains of so-called black yeasts from various sources, 

 and though each strain might be fitted to the description of one or- 

 ganism or another in certain stages of development, they all showed 

 marked transformations of the same general character on continued 

 cultivation, so that he was not convinced that there is more than one 

 species. 



These morphologic transformations have been very completely de- 

 scribed ajid illustrated by Maurizio and Staub." When first isolated 

 the organisms grow as soft, pasty, yeast-like cultures, at first a pale 

 yellow color but rapidly becoming a dark greenish black. Examined 

 at this stage, they show only oval budding yeast cells. If pour-plate 

 cultures are made, the deep colonies, at first lenticular, will eventually 

 sprout out numerous radiating filaments of mycelium that develop 

 lateral clustery and chains of budding cells exactly as in cultures of 



