SEXUAL REPRODUCTION 75 



centrum in the ooplasm, a single nucleus becomes em- 

 bedded in the coenocentrum. A receptive papilla is 

 formed at the point where the antheridium is applied 

 to the wall of the oogonium. An antheridial tube enters 



FIG. 26. Cystopus candidiis. i, the fungus forming white 

 patches on a cabbage leaf; 2, chains of conidia in different 

 stages of development ; 3, conidium germinating and liberating 

 zoospores ; 4, ripe oospore. Fig. i, reduced ; the others mag. 



the oogonium and liberates a nucleus, which comes in 

 contact with the coenocentrum and its contained female 

 nucleus. The two nuclei remain in contact for a short 

 time and then fuse together to form the first nucleus of 

 the oosphere. At this stage the formation of a wall round 



