244 TEXT-BOOK OF FUNGI 



Klebs, Pringshm. Jahrb., 33, p. 573 (1899). 

 Thaxter, Bot. Gaz., 20, p. 517. 



KEY TO THE FAMILIES 



I. Hyphae rudimentary or obsolete. 



A. Archimycetes 



Sexual reproduction by zygospores ; asexual by zoo- 

 spores. Aquatic and endoparasitic in algae, fungi, and in- 

 fusoria, or aerial and endoparasites in plants. Chytridieae. 



Sexual reproduction only known ; sporangia thick-walled, 

 eventually producing zoospores. Aerial and endoparasitic 

 in plants. Protomyceteae. 



II. Hyphae well developed. 



B. Zygomycetes 



Sexual reproduction by conjugation of gametes, form- 

 ing a zygospore. 



Asexual reproduction by spores formed in sporangia. 

 Chlamydospores are also formed by some species. Aerial 

 saprophytes. Mucorineae. 



Asexual reproduction by free conidia borne on hyphae ; 

 also by thick-walled asexual resting-spores. Attacking 

 living insects and producing conidia after the hosts' death. 

 Rarely parasitic or saprophytic on plants. 



Entomophthoreae. 



C. Oomycetes 



Sexual reproduction by antheridia and oogonia, forming 

 oospores. 



Asexual reproduction by conidia usually borne on much- 



