THE YELLOWS. 463 



more and more feeble every year, for several seasons. The roots 

 on digging up the tree, do not appear in the least diseased. 



The soil does not appear materially to increase or lessen the 

 liability to the Yellows, though it first originated, and is most de- 

 structive in light, warm, sandy soils. Trees standing in hard 

 trodden places, as in, or by, a frequented side-walk, often outlive 

 all others. 



Lastly, it is the nearly universal opinion of all orchardists 

 that the Yellows is a contagious disease, spreading gradually, 

 but certainly, from tree to tree through whole orchards. It was 

 conjectured by the late William Prince that this takes place when 

 the trees were in blossom, the contagion being carried from tree 

 to tree in the pollen by bees, and the wind. This view is aques- 

 tionable one, and it is rendered more doubtful by the fact that ex- 

 periments have been made by dusting the pollen of diseased 

 trees upon the blossoms of healthy ones without communicating 

 the Yellows. 



We consider the contagious nature of this malady an unset- 

 tled point. Theoretically, we are disinclined to believe it, as we 

 know nothing analagous to it in the vegetable kingdom. But on 

 the other hand, it would appear to be practically true, and for all 

 practical purposes we would base our advice upon the supposi- 

 tion that the disease is contagious. For it is only in those parts 

 of the Atlantic states where every vestige of a tree showing 

 the Yellows is immediately destroyed, that we have seen a return 

 of the normal health and longevity of the tree.* 



Cause of the Yellows. No writer has yet ventured to assign 

 a theory, supported by any facts, which would explain the cause of 

 this malady. We therefore advance our opinion with some dif- 

 fidence, but yet not without much confidence in its truth. 



We believe the malady called the Yellows to be a constitutional 

 taint existing in many American varieties of the peach, and pro- 

 duced in the first place by bad cultivation, and the consequent 



* The following extract from some remarks on the Yellows by that careful 

 observer, Noyes Darling. Ef-q.,of rs ! ew-Haven,Ct , we recommend as worthy the 

 attention of those who think the disease contagious. They do not seem to in- 

 dicate that the disease spreads from a given point of contagion, but breaks out 

 in spots. It is clear, to our mind, that, in this and hundreds of other similar cases 

 the disease was inherent in the trees, they being the seedlings of diseased 

 parents. 



" W hen the disease commences in a garden or orchard containing a consider- 

 able number of trees it does not attack all at onoe. It breaks out in patches 

 which are progressively enlarged, till eventually all the trees become victims to 

 the- malady. Thus in an orchard of two and a half acres, all the trees were 

 healthy in 1827. The next year two trees on the west side of the orchard, within 

 a rod of each othe-r, took the Yellows. In 1S2D, six trees on the east side of the or- 

 chard were attacked ; five of them standing within a circle of four rods diameter. 

 A similar fact is now apparent in my neighbourhood. A fine lot of 200 young 

 trees, last year in perfect health, now show disease in two spots near the oppo- 

 site ends of the lot, having exactly six diseased trees in each patch contiguous to 

 each other ; while all the other trees are free from any other marks of olseafe." 

 Cultivator. 



