CHAPTEE LIL 



PARASITES OF THE FAMILY SACCHARO- 

 MYCETIDJE. 



Introduction. 



Section I. The genus Endomyces, p. 702. 



Endomyces albicans, p. 702. 

 Section II. The genus Saccharomyces, p. 704. 



1. Saccharomyces tumefaciens, p. 704. 2. Other species of Saccharomyces., p. 705. 

 Section III. The genus Cryptococcus, p. 706. 

 Section IV. The Saccharomycetidse and Cancer, p. 707. 



THE Saccharomycetidse, or yeasts, are unicellular fungi which multiply by 

 budding and in which naked asci are formed freely on the mycelium. Numer- 

 ous pathogenic yeasts have been described, the chief of which will now be 

 shortly dealt with. 



These parasites are sometimes described as Blastomycetes. 1 

 Among the Blastomycetes and with the true yeasts Guiart includes the 

 family of the Oididse, in which reproduction takes place as in the yeasts by 

 budding and by asci, but which may show at one and the same time both a 

 filamentous structure and a yeast-like form. This family, however, includes 

 a number of quite dissimilar species (Chap. XL VIII.). 



Methods. The details of technique for the preparation of microscopical 

 preparations, and of inoculation, will be described under each species. The 

 Saccharomycetidse grow on most of the ordinary neutral or slightly acid 

 laboratory media, and on vegetable decoctions, glycerin-broth, and Nsegeli's 

 medium (p. 39) containing 2 per cent, of glucose. These media solidified 

 with gelatin or agar, as well as glycerin-agar, potato, carrot, etc. are all well 

 suited to their growth. 



t 1 De Beurmann and Gougerot propose the abolition of the word Blastomycetes as a 

 generic term on the ground that it is applied so loosely that one is never sure of its precise 

 significance in any given context. They hold that the use of the word should be strictly 

 limited by its etymology (^Xdcrrr) and JJ.VKTIS, budding fungus), and in that sense it 

 refers, as do the words bacillus, coccus, filament, etc., merely to a morphological appear- 

 ance, and can lay no claim to a generic grouping. 



[These observers classify the parasites dealt with in this chapter in a family, Exoascidse, 

 which they divide into three genera : Saccharomyces, Zymonema and Endomyces to 

 which they provisionally add a fourth, Cryptococcus, to include various other similar 

 but imperfectly known parasites until such time as further investigations shall have shown 

 to which of the other genera they properly belong. ] 



