BLACK lU'ST OK ({RAIX (PUCCINIA (iUAMIMS) 



399 



Fig. 356. — Stage of the Wheat Rust on the Barberry bush, Bcrbcris 

 vulgaris. Left, leaf of Barberry, showing the affected areas which are red- 

 dish, much thickened, and contain many cup-Uke depressions; right, a very 

 much enlarged section through the affected area of the leaf, showing one of 

 the cups (c) with chains of aecidiospores ( X 200) . The very small spores at 

 (p) are the spermatia or pycniospores. 



Fig. 357. — ^Diagram showing the life cycle of the Wheat Rust. A, 

 wheat plants; B, barberry bush; u, uredosporc; t, teleutospore; s, basidio- 

 spores; a, aecidiospore. 



