CHAPTER XXXVII 



BLASTOMYCETES 



THK genus name Blastomyces is used to designate a group of 

 pathogenic fungi having many points in common with the members 

 of the genera Saccharomyces and possibly Torula. It is not 

 certainly known that the forms thus classified are closely related 

 among themselves, for it is a well-known fact that many of the 

 Hyphomycetes, when grown in certain culture-media, will assume 

 a form indistinguishable from the yeasts. It is possible, therefore, 

 that some of the forms described as members of the genus Blasto- 

 myces may be only growth 

 stages of higher forms. Here, 

 again, as has been emphasized 

 in other groups, there is need 

 still for careful morphological 

 and cultural studies of the 

 various species that have been 

 described, for some of them are 

 very imperfectly known. 



An understanding of the 

 morphology of the Blastomyces 

 can best be obtained by a pre- 

 liminary discussion of the Sac- 

 charomyces or true yeasts. 

 The one character which sep- 

 arates this genus from the Hyphomycetes is the difference in the 

 vegetative method of reproduction. This is accomplished by 

 budding. The mother-cell is usually oval or round, and, at 

 various points on its surface, produces small buds, which enlarge 

 and soon separate as independent cells. Occasionally these cells 

 may remain together and become considerably elongated. By 

 continued budding from the tip, a chain of cells is formed 



383 





Fig. 167. Brewer's yeast, Snccha- 

 ronnjces cerevisioe (Glint her). 



