8APOLEQNIACEJE, 



255 



some species the antheridia and oogonia are upon the same 

 plants, and in such cases the fertilization takes place by the 



Pig. 171. 1, end of filament of Saprolegnia. with zoospores (swarm-spores) escap- 

 ing; 2, zoospores of the same at rest; 3, the same more enlarged; 4, the same, 

 germinating : 5, a portion of a filament of AcMi/a. bearing sexual organs, X 120 ; 6, 

 first stage in the development of sexual organs of Achlya ; 7, 8, 9, tucceeding stages ; 

 10, sexual organs of 5, more enlarged, showing the antheridia, and the nearly ripe 

 oogouium, with its contained oosporea. Adapted from Hine. 



direct contact of the antheridium and the passage of its 

 contents into the oogonium by means of a tubular process 



