219 



cases, to mature and transform into the nary form and not attached to a twig, but 



adult stage after the caterpillar has built found in the grass or in shrubs near the 



its cocoon, and thus many parasites lose ground. The two other forms of cocoons 



their lives, since they are not always able are much smaller and more closely 



to escape from the cocoon. A cocoon woven, but differ in size ; female moths as 



will sometimes be found filled with these a rule emerging from the larger cocoons, 



small insects, which have not been able and males from the smaller ones, 



to make their escape, and have thus died Dead larvae are sometimes found in 



in prison. cocoons which are practically of a single 



The adult larva, unlike Prometha, usu- thickness ; there being no space between 



ally spins its cocoon not attached to a the outer and inner layers. The hollow 



leaf, but along a stem ; sometimes, how- skins of the larvae found in such cocoons 



ever, they may be placed in other situa- clearly show that this unusual cocoon is 



tions. due to the influence of parasites upon the 



In about two weeks after the cocoon . larva. 



has been spun, the larva transforms into In the upper open end of the cocoon, 



a chrysalis, in which stage it hibernates kernels of wheat, corn, beechnuts and 



during the winter, and from which it even acorns have been found. How these 



emerges in May or June. get in this position seems to be quite a 



During the winter, when the leaves are puzzle. In opening twenty or thirty 



not on the trees and shrubs which are fre- cocoons, five or six kernels of corn have 



quented by these larvae, a large number been found, thus showing that this oc- 



of cocoons may easily be collected. These currence is by no means rare. Chicka- 



should be kept out of doors during the dees and blue-jays have been given the 



winter, for if kept in a warm room they blame for this work, since these birds are 



will emerge during the winter or so early thought to have the habit of hiding food, 



in the spring that food cannot be secured The inverted outer layer of the cocoon 



for the larvae. clearly shows, in some cases, that the ker- 



If one secure a number of old cocoons, nel of corn has been thrust into the 



from which the moths have failed to cocoon with some force, 



emerge, and cut them open longitudinal- The head of the pupa lies at the small 



ly, he may karn many interesting facts, end of the cocoon, where the texture is 



A dead and dry mummified looking larva less dense, and thus, when it is ready to 



or chrysalis may be found, or, what is transform into the moth, the head is in 



even more interesting, no trace of the the best position for easy escape from the 



larva or chrysalis may be present, but cocoon. But this provision alone is not 



only a mass of small white, paper-like sufficient to make sure the escape. At 



cocoons. These have been left by a col- the time of emergence, the pupa secretes 



ony of little wasp-like parasites which a fluid which escapes from the mouth and 



may occur in such large numbers that by moistening the cocoon softens the 



there is scarcely room for all to spin their glue-like material which binds together 



cocoons, so that on account of being so the threads, thus making it possible for 



closely crowded together, they are the freshly emerging moth to crowd its 



moulded into a mass of cocoons having way between the fibres, and thus secure 



the form of the cavity formerly occupied its freedom. When the moth first crawls 



by the larva. out of the cocoon, its heavy body and 



The cocoons of Cecropia are composed small folded wings show but little resetn- 



of two parchment-like layers of silk blance to the fully-expanded moth. By 



which are generally very dense and degrees, however, the wings expand and 



strong. The space between these two become more rigid, the colors brighten, 



layers contains loosely spun threads of and finally the mature moth is developed, 



silk like a layer of packing material. The The Promethea Moth is only about 



larvae seem normally to luake three varie- one-half the size of Cecropia, and the two 



ties of cocoons ; one kind is very loosely sexes are very different in appearance ; so 



constructed, much larger than the ordi- much so that one would not at all think 



