PLATE 17 
Helminthosporium sativum 
A. —-Portion of barley affected with spot-blotch, showing abundance of foliar lesions 
and withering of lower leaves. XK- Drawn from material collected at Madison, Wis., 
July 22, 1919. 
B. —Portion of barley leaf showing numerous discolored areas due to infection 
with H. sativum. X2. 
C. —Conidia produced on diseased barley, showing characteristic shape, and varia¬ 
tion in size and septation. X500. 
D. —Conidia of H. sativum from diseased barley leaf germinating in water by the 
production of two polar germ tubes. X500. 
Eane.—Conidiophores of H. sativum emerging from stoma and between epidermal 
cells of barley leaf. X 500 
