Fig. 14. — Uncinula spiralis, i, fungus forming white patches 

 on the upper surface of a vine leaf ; 2, part of a vine leaf with the 

 fungus bearing perithecia ; 3, portion of mycelium bearing erect 

 chains of conidia at a, a ; and haustoria which send slender tubes 

 into the living cells of the leaf, b, b, x 300 ; 4, a single free 

 conidium, x 300; 5, a perithecium with its curled appendages, 

 X 100 ; 6, an ascus containing six spores, x 300 ; 7, a free asco- 

 spore, X 300 ; 8, grapes attacked by the disease. 



