TORPIDITY AMONG INSECTS. 61 



multitudes of such young insects ; they hide under the leaves, nestle in 

 rotten wood, burrow in loose earth, creep into snug. crannies, sink beneath 

 the water, and, in almost every situation you can think of, as eggs or 

 grubs or chrysalids, are dead to all the chilling blasts, until the first 

 warm breath of real spring re-vivifies their motionless forms. 



let great numbers of adult insects remain alive through the winter, 

 and some of them require very little encouragement to venture out of 

 their beds on thawing days. The great order of beetles is an example 

 of this, and thousands of small spiders may often be seen running over 

 the snow during a "warm spell" in midwinter. Nor ought the appear- 

 ance of butterflies at the holidays to excite our wonder. Several species 

 of the genus Van&sa, especially V. antiopa and V. progne, spend the 

 season under logs, ledges of rock, etc., and the appearance of a warm 

 sunny day will bring them into activity, when they may be seen flitting 

 about, often in large numbers. The delicacy of these creatures does not 

 seem to prevent their standing severe cold. Arctic species exist, and but- 

 terflies and moths may be found upon the freezing, stormy peaks of the 

 highest mountain-ranges. A specimen of PMlampelus labruscce, a large 

 green moth belonging to the Sphingidce, common in South America and 

 the Antilles, and rarely taken in the United States, was found alive, fresh 

 and beautiful, in Fairbury, Illinois, on January 8, 1874, after a severely 

 cold period, which was followed by fearful winds from the south, causing 

 heavy rains and thunder-storms. The southerly winds, of course, explained 

 the presence of the tropical insect, but its hardihood was noticeable. 



A large amount of information on this general subject is to be found 

 in Mr. S. H. Scudder's valuable book, " Butterflies," chapter viii., headed 

 Seasonal Changes and Histories. 



When, therefore, frosts and heavy storms begin, such insects as do 

 not propose to die that year hide away in warm nooks, crawl behind the 

 loose bark of trees, or poke their way underneath old logs in the woods, 

 where they find hosts of minute companions. When it gets too cold for 

 them to wriggle, they go to sleep and remain so until warmth returns, 

 no matter how long the frosts may hold fast. This is called becoming 

 dormant or torpid, and another prominent instance of it among lowly 

 animals is in the case of the snails. 



As cold weather approaches, the snail crawls under a half-buried stick 

 or stone, and attaching himself to it, aperture upward, by forcing out a 

 little glue at the edge of the shell, throws a curtain of mucus across the 

 aperture. This quickly hardens into a kind of drum-head, and, later, a 

 second, or even a third, is formed inside of it. Through these curtains 



