ASCOMYCETES 363 
Odspores and zygospores tide the plant over unfavorable con- 
ditions and produce new plants when favorable conditions return. 
In combatting the disease-producing Phycomycetes, the control 
of zodspores, conidia, and oéspores must be considered. 
dad —_ 
Fic. 314. — Conjugation in Bread Mold. a, 6, c, and d are successive 
stages in conjugation. At a the short hyphae have just come together, while 
at d the zygospore is formed. e, zygospore developing a new hypha bearing 
asporangium. X about 130. 
Ascomycetes (Sac Fungi and Lichens) 
General Description. — To the Ascomycetes belong the largest 
number of Fungi, and most of them are parasites. Many of our 
most troublesome diseases are caused by these Fungi. Some, 
