THE CATERPILLAR AND THE MOTH
months' solitary confinement in this most inhuman position. Yet, if artificially liberated, the prisoner takes no advantage of the freedom offered. Though it can move a little, it remains coiled (A) and will fold up again if forcibly straightened, thus asserting that it is more comfortable than it looks.
It is surprising that these infant caterpillars can remain inactive in their eggshells all through the summer, when the warmth spurs the vitality of other species and speeds them up to their most rapid growth and development.
Fig. 166. The young tent caterpillar fully formed within the egg by the middle of summer
A, the young caterpillar removed from the egg. B, the caterpillar in natural position within the egg
External conditions in general appear to have much to do with regulating the lives of insects, and if the tent caterpillars in their eggs seem to give proof that the creatures are not entirely the slaves of environment, the truth is probably that all insects are not governed by the same conditions. We have seen that some of the grasshoppers and some of the aphids will not complete their development except after being subjected to freezing temperatures, and so it probably is with the tent caterpillars—it is not warmth, but a period of cold that furnishes the condition necessary to the final completion of their development. Whatever may be the secret source of their patience, however, the young tent caterpillars will bide their time through all the heat of summer, the cold of winter, and not till the buds of the cherry or apple leaves are ready to open the following spring will they awake and gnaw through the inclosing shells against which their faces have been pressing all this while.
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