120 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Key to Families of Saccbaromycetales 



Vegetative cells single or loosely 



attached in irregular colonies, 



mycelium not usually developed, 



asci isolated, not differentiated 



from vegetative cells 1. Saccharomycetacese, p. 120. 



Vegetative ceUs forming a mycelium, 



asci terminal, or intercalary, 



differentiated from mycelium. . 2. Endomycetaces, p. 122. 



The first family, the yeasts, to which belong the majority of the 

 species of the order, is of prime importance in fermentation. A 



Fio. 82. — Yeast plant-bodiee, showing 

 budding and sporulation. After 

 Coulter and Rees. 



few species are known to cause animal diseases; others are found 

 associated with the slime fluxes. 



Saccharomycetaceae 



Vegetative cells separate or few together, never truly filamen- 

 tous, propagating by buds; asci globose to elliptic, 1 to 8-spored; 

 growing typically in sugary or starchy materials. 



