256 STATE POMOLOGICAL SOCIETY. 



Impulsively concluding that birds, insects, man or boast coming in contact 

 with this delicate substance under favorable conditions of temperature and 

 moisture might thus easily displace and convey it from tree to tree, finding a 

 congenial foothold in some and failing in others, impregnating those near at 

 hand or at distant points as the conditions might prove more or less favorable, 

 I accordingly gathered a handful of these fungus covered leaves moistened 

 ■with the morning dew, and selecting a vigorous and healtliy tree some 

 rods distant, and having previously observed that the disease in 

 most instances presents its first appearance on a central or southeastern 

 branch (probably because birds and insects in the cool dewy morning find 

 these sunny spots most to their liking for the arrangement of their toilet), I 

 proceeded to the selection of a branch on the sunny side, and the handful of 

 infected leaves was gently brought in contact with both surfaces of a number 

 of the moist leaves on the liealthy tree. Almost daily visits to this 

 tree followed for the ensuing two weeks, when no change being perceptible, 

 they were discontinued, and in the subsequent hurry of harvesting, my grape 

 crop, the experiment was forgotten until some three weeks later. Passing 

 this tree I was surprised to find a portion of the leaves on the vaccinated branch 

 assuming a wilted appearance, and the unmistakable half moon shape which 

 most of our members now recognize as the premonitory symptoms of the 

 presence of the disease. 



It only remains to be added that before the tree was finally divested of its 

 foliage by frost, this peculiar crescent form was distinctly apparent in 

 nearly every leaf upon this branch, and the entire tree I have little doubt will 

 next season develop the disease in an advanced stage. I may also note in evi- 

 dence of my belief that birds and insects may be, and probably are, the 

 unwitting vehicles for spreading broadcast the contagion : that at least four- 

 fifths of the infected trees in my orchard during the past season were border- 

 ing on a ravine densely overgrown with weeds and brambles, making a favor- 

 ite resort for both birds and insects. These birds and, j^ossibly also, the 

 insects, may and probably do migrate from infected districts mainly during 

 the nigiit or early dawn, flitting from tree to tree, from orchard to orchard, 

 their limbs and plumage thus becoming the best possible means of displacing 

 and conveying these delicate germs, and anon disseminating them by contact 

 -with the foliage of healthv trees elsewhere. Indeed, in no other wav can 

 its erratic spread bo reasonably accounted for. But besides the numerous 

 birds finding here a congenial basking place in the early morning's sunshine, as 

 also a flattering outlook for the conventional ^^ early worm " during the early 

 summer, three or four and frequently ten times the number of curculia 

 were caught from the row of trees adjacent to this ravine than were found 

 elsewhere in the orchard, the number always diminishing in proportion as the 

 distance increased. This, in connection with the fact before stated, that the 

 larger percentage of the diseased trees to be found in my orchard were in these 

 identical two rows where birds and curculio were always most abundant, is cer- 

 tainly suggestive of a reason for tlie assumption that birds, insects, and yel- 

 lows, have, to say the least, some curious coincidental connection. 



And now, in conclusion, let me add that this single experiment is not offered 

 as proof positive and infallible, but rather as a suggestion, with the hope and 

 expectation that all interested will make similar tests, and if conducted with 

 due reference to the extreme delicacy of the laws which govern the growth 

 and dissemination of these minute wonders in nature's economy, I have no 

 doubt as to the attaiument of like results; and if thiis theory may be practi- 



