ArsenicA i, Poisoning oe Fruit Trees. 5 
in sharp contrast to the healthy tissue. The disease soon kills the bark and 
it dries down to the wood, taking on a dark brown color. Two seasons are 
required for the disease to kill the trees. The first season the trunk is girdled 
and the foliage drops early. This early ripening of the foliage is often the 
most prominent symptom and diseased trees can be easily picked out in the 
early fall. (See Plate I., lower figure). Trees showing an early bronzing of 
the foliage are generally found girdled by this disease. The second season 
the tree starts Into leaf as the normal tree, generally setting fruit, and dies 
in mid-summer, the fruit and leaves clinging. (See Plate I., upper figure). 
The disease seems to be infectious, as the trees appear in groups, and in 
many cases it appears as though it were carried by water. When a diseased 
tree is found, several more are generally found in the same row. However, 
other varieties besides the Ben Davis and Gano may stand in the same row 
with diseased trees on either side and show no sign of contracting the disease. 
The fact that Ben Davis and Gano are very tender as regards the applica¬ 
tion of arsenical sprays has suggested to my mind that the trouble may be 
due to arsenic collecting about the crown of the tree and killing the bark. 
However, the fact that trees sprayed with arsenate of lead and arsenite of 
lime are alike affected, seems to be cntrary to such a hypothesis. 
“Prompt removal of the trees affected seems at present to be the only 
treatment that can be suggested. Reports indicate that the disease has only 
been in the orchards two or three years at the most. Soil conditions seem 
to have no relation to the disease, as it is found on all kinds of soils.” 
The description of the affected trees as given by Mr. Whip¬ 
ple is, I believe, entirely reliable as he has been in this field for 
several years, and has had opportunity to observe these trees at 
all stages of the affection. I can, in fact, corroborate his state¬ 
ments as Mr. Whipple was kind enough last Autumn and again 
this spring to point out a number of these trees at different stages 
in the process of dying. While the appearance of brown spots 
on the trunk of the tree are observable early in the progress of 
this trouble, they are not the seat of the trouble, which beginning- 
on the crown of the tree has by this time advanced to the trunk. 
Whether it ever begins on the roots below the crown is not at 
present known. It is not to be wondered at that Mr. Whipple, 
without a definite knowledge of the cause of the trouble, states 
that the disease seems to be infectious'. He pointed out to me a 
row of Ben Davis trees, four of which were already dead, 
with leaves and fruit still clinging to them. In the adjoining row 
was another tree which was likewise dying, as I now recall it—this 
tree stood at a point where the irrrigation water crossed from the 
row of four dead Ben Davis trees and passed close to this one, 
seemingly justifying Mr. Whipple’s inference that the disease is 
infectious and also the further statement, “and in many cases 
it appears as though it were carried by water.” My explana¬ 
tion of this is a different one as will appear in a future para¬ 
graph. 
Mr. Whipple in the next sentence, calls attention to an im¬ 
portant fact, i. e.—that the two varieties, Ben Davis and Gano, 
are very sensitive to arsenical sprays, and suggests the possibility 
that the trouble may be due to arsenical poisoning, but seems to 
dismiss this as an untenable hypothesis. Another point in Mr. 
