10 



Donald Reddick and V. B. Stewart 



TABLE 1 (concluded) 



The trees were removed on May 24, 1920. About two-thirds of them 

 were pulled by hitching a team directly to them; the remainder were 

 pulled with blocks. There was not the least indication that gall-free 

 trees pulled more easily than those originally bearing galls. One tree, 

 B-6, broke off at the surface of the ground, but this seems to have been 

 due to weakening from borers and to the large size of the roots. 



On examining the roots it could not be detected, from their appearance, 

 size, or length, that there was any difference between the roots of galled 

 trees and those of trees free from galls. The most surprising thing revealed 

 by examination of the roots was that in many instances the original galls 

 had disappeared completely. This was true in practically all cases in 

 which the original tree had a long rootstock and the gall was located 

 near the base of the stock. All the main roots issued from the stock 

 near the surface of the ground, due perhaps to the nature of the subsoil. 

 In most cases in which the gall was located on a lateral root, both root 

 and gall had disappeared, but the same disappearance of original roots 

 was noted in healthy trees also. 



Summary for the apple experiment 



The data in table 1 may be summarized in a few words. In no case 

 is there indication that the presence of crown-gall on the roots of these 

 apple trees interfered in any way with growth. The galls had largely 



