FIG. 51. Peronospora -viticola,z. parasitic fungus very destruc- 

 tive to the vine, i, white patches of the conidial form of fruit on 

 a vine leaf; 2, group of conidiophores issuing through a stoma 

 and bearing conidia ; 3, three conidia ; 4, conidia producing zoo- 

 spores, in a, the zoospores are yet within the conidium ; b, 

 two zoospores that have escaped from the conidium ; 5, mature 

 oospore or resting-spore ; 6, an oospore germinating and pro- 

 ducing the conidial form of fruit ; 7, autumnal form of shortened 

 conidiophore bearing a few large conidia. Fig. i, reduced; the 

 remainder highly mag. (Figs. 6 and 7 after Prillieux.) 



