31 



than any other arsenical mixture, but when boiled in water before dilution it is the most 

 injurious to foliage, showing plainly that it is the dissolved arsenic which burns the leaves, 

 since in a cold, fresh mixture less than 1 per cent, of the arsenic is actually dissolved. 

 Paris green, his experiments showed, injured the leaves more than the cold, white arsenic 

 mixture, and London purple more than the Paris green, but both were less harmful 

 than the boiled solution of white arsenic. All mixtures were of uniform strength, and 

 the tests were most carefully made. 



Professor Cook agreed with Professor Gillette as to the relative merits of Paris green 

 and London purple, but Professor Riley and Dr. Lintner were inclined to stand by London 

 purple on account of color, price and well-proven value. 



A discussion of great importance to the members of the association was started by 

 Professor Forbes, of Illinois, in a paper on " Office and Laboratory Organization. Pro- 

 fessor Bruner, of Nebraska, presented a paper on the corn root-worm, which he instanced 

 as a striking example of the ever-recurring change of habit among insects, which is 

 continually making new pests from heretofore unnoticed species. 



The topic of co-operation was long and thoroughly discussed and many valuable sug- 

 gestions were made, and the outcome was that a committee, consisting of Professors Riley, 

 Forbes and Oook, Dr. Lintner, and Professor J. H. Comstock, of Cornell University, was 

 appointed to consider and report to the next annual meeting upon a method or methods 

 to secure co-operation among the'members of the association. 



Other papers were read of a more technical character and consequently of a less 

 general interest, and when the hour of adjournment arrived on the evening of the third 

 day it was found that the programme had not been finished, and the members separated 

 with regret to take up once more in their respective States active warfare against the 

 great and ever-increasing armies of insect pests. 



POPULAR AND ECONOMIC ENTOMOLOGY. 



• WINTER COLLECTING. 



In the continuous chain of nature, great interest will be found at every link, and 

 things unexpected, strange and of marvellous beauty will appear at every point. Even 

 in Canada, snow and ice-bound for so many months in the year, there is much collecting 

 which can be done in the winter. A favorite occupation of the writer is to go off collect- 

 ing with a congenial companion upon snow-shoes. The charm of this pleasant exercise, 

 in which, supported by the light snow-shoes, one can visit places inaccessible during the 

 summer, is in no way diminished by being able to take home with you specimens which 

 will afford ample occupation for many evenings. Starting off in a straight line, many 

 objects of interest are met with as we go along across fields and fences, through woods 

 and swamps and over rivers, hills or even mountains, all levelled and smoothed down to 

 an even surface by their thick covering of ice and snow. In passing through the woods 

 and swamps, cocoons are eagerly looked for on the slender boughs of trees and shrubs. 

 It is seldom that we are not rewarded with cocoons of the large Emperor moths. In 

 crevices of bark and beneath moss, many hibernating insects are discovered of several 

 orders ; larvae of moths and chrysalids of butterflies, bettles and hemiptera. One of our 

 annual trips is to a certain tree for the pretty little homopteron, which forms galls on 

 the leaf of the hack-berry, (Psylla celtidis-mamma, Riley) and which passes the winter in 

 a torpid state beneath tho scales of the bark of the hack-berry, the color of which it 

 closely resembles. In passing through the swamps, tufts of moss are pulled from any 

 exposed hummocks, to be picked to pieces at home when they have thawed out. There 

 will be found many treasures which we have not found in any other way. Every cluster 

 of leaves adhering to a deciduous tree, or swelling upon a stem, has to be examined for 

 the cause, and if it prove to be the work of insects, must be put into the bag for exami- 

 nation. The only apparatus necessary for these expeditions is a bag slung over thd 

 shoulder and a stick with a hook on one end and a spike on the other. The bag acts as 



