Bull. 25, Div. Veg. Phys. & Patn., U, S. Oept of Agriculture, 



Plate V. 



CO 



■V 

 o 



O 



■a 



I 

 o 



3) 

 in 



CO 



O 

 -n 



■V 

 O 



r 

 -< 



T3 

 O 



33 



C 



00 



o 

 o 



CO 

 > 



33 



Ti 



33 



