Bui. 28, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate IV. 



31 



> 



z 

 o 

 o 



H 



m 

 m 



O 



c 



o 



> 



H Z 

 m (7) 



> z 



r- 



> O 



-< 

 73 



m 



D 



o 



z 



z 

 m 

 > 



3) 

 > 



z 



o 



en 

 m 



to 



a> 



m 

 o 



H 

 O 

 z 



7^ 



■<^ m 



> o 



H O 



c Z 



N 



m 



> 



-J z 



CD 



O 



c 



O 



z 

 o 



m 



T) 



