THE CANADIAN ENTOMOLOGIST 269 



log, and the characteristic smell was very apparent. And strange to ?ay, the 

 insects made themselves unexpectedly manifest to another sense also. Rivalling 

 the fairy- talc hero who could hear the grass growing, to my surprise I found I 

 could hear the springtails leaping on the dead leaves. So many hundreds of 

 them were jumping at the same moment, that the myriad simultaneous impacts 

 b(x^ame audible even to the coarse human sense of hearing, and sounded like 

 the tin>- rain we must suppose fell in Lilliput. 



Watching any general movement of these insects is like watching the hour 

 hand of a clock. They were evidently spreading out from this focus, but so 

 slowly in spite of all their leaping and crawling hither and thither, that very 

 little change could be noticed during the thirty or forty minutes that I observed 

 them. When I returned to the spot the evening of the following day, they had 

 as usual nearly all disappeared. On the leaves were many white patches of 

 cast skins, and a few stragglers were still crawling over the log, but the millions 

 of yesterday were gone. 



These eruptions of Achorntes socialis and its congeners are due to over- 

 crowding of the domicile, and in that respect they parallel the swarming of the 

 bees and ants. But there the resemblance stops, for, of course, the spring- 

 tails have no special organization whatever, and those found living in colonies 

 are m.erely kept together by a common interest in some food supply or other 

 favourable condition. When the place becomes too small to support them, 

 practic?-lly the whole population leaves at the same time, each individual to 

 seek his own private fortune, and the old home is completely abandoned. One 

 obvious advantage of the movement, in addition to a more abundant forage, 

 is the cross-breeding that takes place between dififerent, colonies. The in- 

 creased vigour of the race which accrues no doubt more than counterbalances 

 the large mortality among the emigrants. - 



The Collembola as an order have never attracted many students, and it 

 is not likely that this article will do anything to increase the number, but " should 

 one heart throb higher at its sway," it would be a pity not to encourage the 

 aspirant to springtail lore, and so I will say something about collecting methods. 



The Collembolist's collecting outfit is simple, inexpensive and not at all 

 bulky, but as the insects are found in a variety of situations, several different 

 pieces of apparatus are necessary to capture them. Among the first requisites 

 are the small straight-'sided bottles without shoulder or lip, known as shell 

 vials. For general use in collecting and for storage purposes, round- bottomed 

 shell vials about 50 mm. long by 10 mm. in diameter, as recommended by Dr. 

 J. \\' Folsom, are best. But for very minute specimens even smaller bottles 

 than these are often desirable, and I usually carry a few vials 40 mm. and 25 

 mm. long by 6 mm. or 7 mm. in diameter. If not obtainable from stock, any 

 dealer will have such bottles as these made to order at a small cost per gross. 



In summer a small fragment of damp, rotten wood or a piece of a moist, 

 dead leaf tamped down into the bottom of the vial will keep the specimen from 

 dying of aridity until you get them home. In winter, when everything out- 

 doors is dried up by the frost, my bottles are furnished with a scrap of filter 

 paper, which can be moistened when required by dropping a granule or two of 

 snow on to it. But one must be careful not to get the bottles too wet inside, 

 or the insects will drown in the water film. 



