172 



MANUAL OF MODEKN VITICULTUKE. 



Cassady, Creveling, Isabella, lona, Mottled, Maxatawney y 

 Union- Village, Rebecca, Walter; Hybrids : Delaware, Aga- 

 wam, Allen's Hybrid, Aminia, Barry, Black Defiance, 

 Croton, Irwing, Massassoit, Merrimack, Salem, Aittuchon, 

 Canada, Cornucopia, Othello. 



This disease is caused by the action of a cryptogamic 

 parasite, the Plasmopara viticola (Berlese and de Toni) 



Fig. 150. Diagram of a vine leaf attacked by Plasmopara (after Viala). 

 A, Upper face, pallisade parenchyma ; B, Under- face, spongy paren- 

 chyma ; D, Vein ; E, Epidermis of the upper-face ; F, Epidermis of 

 the under-face. a, Mycelium of the fungus growing between the 

 cells of the tissues, after entering through the epidermis of the under- 

 face ; 6, Antheridia and oogonium uniting ; *, Stomatum from which 

 the shoots carrying the conidia emerge ; p, Fructiferous shoot, with 

 summer spores or conidia, <% e ; , t t Sterigmata. 



closely related to the Peronospora of the potato (Phytopht 

 Infestans, of Bary). The name of mildew was given 

 this disease by the Americans. 



ora 

 given to* 



