PIATB-3 
A. —Beginning of apple stem-tumor at X , and X Woolly apple aphis abundant 
at these places. Early Harvest apple tree, Maryland. 
B. —Type of stem-tumor on Martin tree, which shows few or no masses of aborted 
roots. At X a few are ready to burst through the bark. Platings were made from 
tumor X. No crowngall organism was present. Woolly apple aphids were on these 
tumors; one-third natural size. 
C. —Woolly apple aphis root galls on Buckskin apple tree; natural size. Same tree 
from which stems B and C of Plate 2 were taken. 
D. —Early stage of apple stem-tumor on Buckskin apple tree from Virginia. X5* 
Negative platings were made from these also. Note presence of woolly apple aphis. 
