Bui. 24, Div. Veg. Phys. & Path., U. S. Dept. of Agriculture. 



Plate X. 



O 



o 



TJ 

 O 

 W 



H 

 m 



O 



c 



CO 

 CO 



CD 



< 



> 



X 

 H 

 O 

 Z 

 CO 



CO 

 I 

 O 



S 



CO 

 > 



m 



CO 



I 

 m 



TJ 

 XI 



O 



m 



z 



H 

 I 



m 



r 

 > 



CO 



H 



O 

 3J 



o 



CO 

 CO 



