Bui. 1298, U. S. Dept. of Agriculture 
PLATE XIII 
i-: N C c S i ^ 
•OrR s mSI P. 
p g tn g- 
C-C. 
3^ 
' ® f 3 ffl 
o p ° » 
p o o - =: 
fail 
3 g- •Ssti' 
2 v-: = ~ ^ 
^f 
"S f 
