YEASTS AND MOLDS 



295 



3. Other species of Mucor are reported as causing pathologic con- 

 ditions in man and in lower animals. Some are the cause of fatal infectious 

 diseases in such household pests as the common fly. Others attack fruits, 

 as pears, figs in particular, leather goods as gloves, etc. 

 II. Ascomycetes. Spores formed in asci (sacs). 

 i. Saccharomycetes yeasts proper. 



a. Saccharomyces cerevisea. This name is applied to many 

 species or varieties of yeasts concerned in fermentation 

 processes, as in beer, wine and sake making. 



FIG. 70. Saccharomyces cerevisece. 



The form or variety known as brewers' top yeast. 

 (Oberhefe.) 



b. Saccharomyces angina. Pathogenic. 



c. Saccharomyces ellipsoides. Common in fermenting fruits, 

 jams, jellies, fruit juices, etc. Other species are active 

 in various vegetable food fermentations. 



d. Saccharomyces Blanchardi. Pathogenic. 



e. Endomyces albicans. Pathogenic, causes thrush. 



f. Cryptococcus Gilchristi. Pathogenic; general infections. 



g. Cryptococcus hominis. Pathogenic. 

 2. Gymnoascomycetes. 



a. Trichophyton tonsurans. Pathogenic, causes scalp dis- 

 ease (ringworm), also attacks other external tissues. 



