PLATE 13 
Penetration of a leaf of the castor bean by germinating conidia (except I and J). 
A. —Penetration of cuticle by means of a very fine outgrowth almost directly from 
the spore. 
B. —Similar stage of penetration by tip of a germ tube. Swelling of the cuticle 
aeems to be evident. 
C. —Two cases of penetration into the cuticle. 
D. —A group of germinating conidia. In two places the cuticle has been entered 
but not completely penetrated. Nof injury was evident in the epidermal cells. 
E. —Another case of partial penetration. 
F. —Penetration accomplished and hyphae growing rapidly into the host cells. 
G. —Penetration accomplished; the hypha has advanced into the subepidermal 
layer of host cells. Note the swollen cuticle and the clear region about the penetrating 
hypha, indicating 4 hat some dissolving action has taken place. 
H. —Lower part of hypha that has penetrated the cuticle. Apparent dissolving 
action also seen here. 
I. J.—Ansastomosis, or growing together of hyphae in a young culture on clear corn 
meal agar. 
The material was fixed 24 hours after inoculation, some of it showing only very slight 
injury. Magnification is indicated by the scales, each space of which represents 10 fx. 
