18 CAUSE AND NATURE OF CROWN-GALL 



on the east side was also badly infested. The small gall was 

 removed February 26, 1S96, and the diseased root completely 

 cut away. The fungicide and tar were applied as in previous 

 examples. At the time of the second examination, two months 

 later, no evidences of returning galls were observed. In Sep- 

 tember, five mouths later, the gall had reappeared where the 

 root had been cut away, and several new galls had developed 

 on adjacent roots. The wound on the crown had completely 

 healed. Normal callus tissue had entirely covered the wound 

 made in removing the gall. The following year the tree was 

 badly diseased and probably beyond remedy. The tree died 

 during the summer of 1898. The evidence regarding the other 

 trees treated is practically a repetition of the examples cited. 



EFFECT OF BORDEAUX MIXTURE ON THE DISEASE. 



The results that I obtained from these experiments seem to 

 indicate that the Bordeaux mixture at its normal strength is at 

 best but a poor remedy for the disease. This, however, will 

 be more fully discussed under the subject of remedies and pre- 

 ventive measures. 



OBSERVATIONS ON SEEDLINGS IX THE GLENDALE ORCHARD. 



In February, 1898, I made a personal examination of a large 

 number of seedlings in the Glendale orchard. 23 These seedlings 

 were the result of almonds dropping from the trees and becom- 

 ing covered with soil at times of cultivation. Not infrequently 

 from fifty to seventy seedlings were growing under a single tree. 

 These seedlings were only a few months old and from six to thirty 

 inches high. I examined some four hundred of them and did 

 not find a single plant infested with crown-gall when growing 

 under trees which' were free from the disease. On the other 

 hand, under one badly diseased tree, five diseased seedlings were 

 dug up within twelve inches of the bole of the tree. On this 

 tree the disease formed large excrescences at the surface of the 

 ground. In other cases one or more diseased seedlings were 



-*See Ann. Rept. Ariz. Agr'l Exp. Sta. 1899, 2 3 s - 



