_ ducing a satisfactory cure, for many of the temporary 1M, 
974 On the Microscopic and General Characters of (December, 
and thus save the trees. Those persons advancing some of them 
claim that their modus operandi is a sure and active agent in 
bringing about the desired end. But most of the modes are 
simply theoretical and always fail. In most cases when a cure 
has been reported, it has afterwards been proven that the tree did 
not have the yellows at ail. For example, one who attributed 
the yellows to an animal origin, used Paris green, throwing it 
over the tree with a pump, and the next year the trees that he 
supposed to be diseased were in a healthy bearing condition. It 
was afterwards shown that the symptoms of the yellows were 
X 406 
_ Fic. 6.—Hairs on the skin of the peach (x 405). Drawn with camera lucida. 
produced indeed by an animal, but that animal was simply Whi - 
plant louse! The tree being covered with them, the Paris bie 2 
was an effective agent in ridding the orchard of its pest. ; ine 
Some have used hot or boiligg water, pouring it ie a) 
roots of the trees, and in many cases they have reported the . a a a 
ease reduced; but in every case that has come under my obset- 
vation it has failed, . ciel 
_ It is not at all surprising that the means used—including a 
whole category of remedies—have often been reported ne ae 
yjuries liable 
10 come upon a tree, will, in most instances, produce many yé x 
ae of the yellows ; these are the cases ‘that ae 
