172 YEASTS AND MOULDS 



the connection with the parent dissolves and the new cell 

 is free. Spores have been observed within the yeast cells, 

 and these develop into adult cells when the old cell ruptures. 

 Yeasts grow upon nearly any organic substance providing 

 there is moisture. The best media and temperatures vary 

 with the species. The kinds pathogenic for man grow best 

 upon foodstuffs containing simple sugars, but may thrive 

 also on complex substances. They are grown with reasonable 

 ease in the laboratory, but care must be used to get them in 

 pure cultures as their development is slow. Their peculiar 



/ <& *#% 



/.-sflNP 



FIG. 54. Saccharomyces Busse. X 350 diameters. (From Kolle and 

 Wassermann.) 



effect upon carbohydrate-containing stuffs is due to their 

 enzyme which has the power of making alcohol. How much 

 effect this has upon the production of disease in man is not 

 known. 



Blastomycosis. The disease produced by yeasts in man 

 called Blastomycosis, and the causative agent is called 

 Saccharomyces Busse, after the man who first described it. 

 By the first, a genus name, it is seen to belong to the same 

 group as the principal beer-making yeast, Saccharomyces 

 cerevisice. It is not known just how the disease is contracted, 

 but the yeast probably enters wounds, cracks, or hair follicles. 



