FIG. 61. Peronospora viticola, a destructive parasite attacking 

 the vine, and known as vine mildew, i , under surface of vine leaf, 

 showing patches of white mildew ; 2, a group of conidiophores, 

 emerging through a stoma of the leaf ; 3, the conidia more highly 

 mag. ; 4, conidia liberating zoospoi es ; 5, mature oospore or rest- 

 ing-spore, formed in the tissue of the leaf ; 6, an oospore germ- 

 inating, and producing a conidiophore ; 7, autumnal form of 

 conidiophore with a very short stem, and bearing only few 

 conidia. Fig. i, reduced ; the remainder highly mag. 

 R 



