PLATE 7 
Petri dish cultures of Phytopkthora parasitica var. rhei. 
A. —A contaminated culture. 
B. —The same strain secured in pure culture by inoculating into ail apple and 
reisolating from the advancing edge of decay. 
C. — Phytopkthora parasitica var. rhei (a) and Phytopkthora terrestris Sherb. (b) com¬ 
pared, on corn meal agar. 
