FINAL DEDUCTIONS. 43 



One of the most striking examples which has come under observation 

 is a tree on the home farm of James S. Harris, near Still Pond, Maryland. 

 Since one case in point is as good as many, I have been at some pains 

 to learn the history of this tree. This tree is 36 years old. It is one 

 of a number of accidental seedlings which came up from stones thrown 

 out in the fall of 1854. It then stood back of an old shop. This was 

 afterwards removed and other changes made so that for quite a good 

 many years the tree has stood in sod ground, in the lawn, somewhat 

 isolated from other peach trees. It was budded by Mr. Harris himself 

 in the fall of 1855, and has been under his observation and care ever 

 since, with exception only of a few years when he did not reside on this 

 farm. The variety is Crawford's Early. The tree has been hardy and 

 productive. Its last crop was in 1888, since when, in common with 

 other trees in that region and owing solely to unfavorable seasons, 

 it has borne no fruit. The tree is about 25 feet high and has a 

 good top ; the trunk is nearly a foot in diameter and still quite well 

 preserved. I have seen this tree each year since 1887, and always it 

 seemed to me good for another 10 years. This tree was budded from 

 a neighboring tree when there was no yellows in the vicinity. Some 

 years after, perhaps 10, the disease appeared and gradually de- 

 stroyed many younger trees upon the same farm, one of the badly 

 affected orchards being within a stone's throw of this tree. The disease 

 has increased from that time to this, and has been very destructive 

 for the last 5 or 6 years in all that region. This old tree, however, kept 

 on the even tenor of its vigor until the summer of 1890. Then for the 

 first time it developed unmistakable symptoms of yellows on one small 

 limb (plate xxvin). Next year, undoubtedly, the disease will be mani- 

 fest on other limbs if it does not involve the whole tree.* 



Admitting the contagious nature of yellows, and this, I think, can 

 be doubted no longer, I am at a loss to explain the appearance of the 

 disease in middle-aged and old trees except by infection from without. 

 If such be the case, then, of course, every tree which becomes affected 

 is a fresh source of danger, and ought to be removed and destroyed as 

 soon as possible. 



V CONCLUSIONS. 



The intelligent reader will draw his own conclusions. It is not out 

 of place, however, for me to present my view of the case. This is as 

 follows : 



FACTS ESTABLISHED. 



(1) The disease is contagious. It seems to me that Experiments 1, 

 2, and 5 settle this point beyond dispute. 



* Examined July 24, 1891. The diseased limb and the adjoining healthy one have 

 been removed and the remainder of the tree shows no symptoms. The tree bears 

 green peaches. 



