268 THE CANADIAN ENTOMOLOGIST 



the openings by which they reached the surface, they simply work their way 

 into the snow wherever they may be. Probably when the bed of snow is shallow 

 and soft, they soon get down to the ground, but on this occasion their progress 

 earthwards was decidedly slow. For more than a week after they had left 

 the surface they were still to be found scattered through the snow at various 

 depths. Trenches dug in the snow at several points revealed three crusts —  

 the result of thaws earlier in the winter^each about an inch thick and separated 

 one from the other by from three to seven inches of loose, dry snow. The tiny 

 creatures seemed to have had little trouble in finding passages through the 

 upper crusts, but the bottom crust was solid ice, and here in the first days of my 

 investigations I found the snow-fleas accumulated in considerable numbers. 

 Later on, these insects gradually disappeared. Although lacking any direct 

 evidence, I am of the opinion that by degrees many of them worked their way 

 along through the snow until they encountered some twig or root that pierced 

 the crust and enabled them to crawl down to the earth. There is no doubt, 

 however, that a very large number of the adventurers perish. The fact is that 

 in six years' observation of their winter habits, I have never seen two large 

 emergencies occurring in the same locality, indicates that a great destruction of 

 the insects must take place on every excursion. 



After all that has been said about their appearances in the winter, it might 

 be thought that the insects only come out when the ground is covered with 

 snow. The truth is that in favourable weather they emerge just as readily when 

 the ground is bare, but, of course, they do not then attract attention as when 

 they are set off by the vivid background of the snow. 



One calm misty morning in that golden prime of spring when the first wild 

 flowers are all out and the mosquitoes aren't, I came down through the woods, 

 leafless as yet, to a marsh that was flooded a couple of feet deep with the high 

 water from the Ottawa River. The whole half mile of swamp, I remember, 

 was ringing from end to end with an astonishing chorus of frogs, — a great \olume 

 of sound, but so steady and sustained that presently, like the music of the 

 spheres, it went out of my consciousness, until suddenly I was made aware of 

 it again by the startling abruptness with which it stopped : a marsh hawk sweep- 

 ing over the water had struck the massed choirs instantaneously dumb. As I 

 worked my way through the alders along the edge of the water, I noticed a good 

 many A socialis climbing in the withered "beaver hay," the blue black colour 

 of the minute insects rendering them conspicuous in the yellow grass As I 

 advanced they became thicker, and here and there strings of them floated 

 down runlets from the woods And then I came on the springtail metropolis. 

 It was a large, moss-covered log so rotten that its species could not be 

 determined, but it was probably a pine. It was bedded on the dead leaves of 

 yester year just at the edge of the water, and from a crevice in its brown crumb- 

 ling side, A. socialis were emerging in solid dark blue masses. The easiest way 

 to appraise them would have been by dry measures. There must have been 

 something over an imperial pint of them visible, and more were continually 

 coming out of the log. On the damp leaves they were gathered into several 

 patches six inches in diameter and fully half an inch thick. I filled a number 

 of collecting tubes chockfull by merely scooping two or three times into these 

 masses. A fine spray of leaping insects played continually over the side of the 



