PHTCOPHrrA. 



155 



germ-cell. The protoplasm of the antherid is thus trans- 

 ferred directly to the germ-cell CFig. 84, A, B, G). After 



■9r 



^orrr 



FiQ. 83.— Germination of the oonldia of Potato-mildew, a, 6, e, forma- 

 tion of zoospores ; d, growth of zoBspores ; sp, a zoospore growing into the 

 cells of the plant, e, %. : Magnified about 400 times. 



Fig. 84.— Sexual organs of a Mildew, o, oogones; n, antherlds. A, 

 youngest stage ; B and C, older stages. Magnified 350 times. 



Fig. 85.— Resting spores of White Rust of Peppergrass; at ^. still sur- 

 rounded by oogone. B, C, formation of zoospores: X), free zoospores. 

 Magnified 400 times. 



fertilization the germ-cell secretes a thick double wall, and 

 so becomes a resting spore. 



