48 



PROTISTS AND DISEASE 



they are very small. They consist of nucleolus, nuclear 

 plasm, and membrane, resembling those of Saprolegnia, 

 Ustilago (smut), and Uredo (rust). The nuclei may become 



m; 



FIG. 10. PIPTOCEPHALIS FRESENIANA. M, hypha of M . mucedo ; m, hyphae 

 of Piptocephalis ; H, haustoria ; Z, zygospore ; *, suspensors ; z, 

 stage in formation of zygospore ; c, conidia. Modified from de Bary, 

 after Brefeld. 



elongated in the direction of the hypha. Similar nuclei are 

 found in the sporangium, the plasm of which surrounds a 

 vacuole, and subdivides into spores, each of which contains 



