PI.ATE 20 
Helminthosporium monoceras 
A. —Portion of plant of Echinochloa crusgalli attacked by H. monoceras showing 
presence of spots on leaf blades and of diffused discoloration on basal sheaths. X^. 
B. —Portion of leaf blade of Echinochloa crusgalli attacked by H. monoceras showing 
variation in size of spots. XM- 
Ca-b.—Group of conidiophores emerging from stoma of host; showing also mycelium 
ramifying in mesophyll as revealed in glycerine preparations stained with eosin. 
X500- 
Da-n.—Conidia from Echinochloa crusgalli collected at Port Washington, N. Y., 
September 20, 1920, showing variation in size, shape, and septation. X500. 
Ea-c.—Conidia from Echinochloa crusgalli germinating by the production of two 
polar germ tubes. X500. 
