THE AMERICAN SILK-WORMS 



275 



a long time and undoubtedly thus escapes notice, as it resembles 

 a serrate edged leaf. 



The cocoon. — This is quite different in shape from that of the 

 cecropia or promethea. It is a broad, blunt oval and is spun within 

 at least two leaves and often with other leaves in the vicinity 

 attached. Usually when the leaves fall the cocoons go with them 

 and lie safely under the snow all winter. However, during recent 

 years we have found many polyphemus cocoons fastened to twigs 

 and remaining on the tree all winter. Whether this is a chance 



happening or 

 the beginning 

 of a new habit, 

 we are unable 

 to say. The 

 cocoon is very 

 [solid, and is 

 not double 

 walled, like 

 that of the 

 cecropia. 



The pupa. — 

 This is almost 

 globular i n 

 shape and 

 shows the an- 

 Polyphemus cocoon cut open showing the pupa. The vring- tennae and 

 cases and antenna show plainly. 



the wing pads 



ver\' plainly. 

 The moth. — When the moth breaks open the pupa skin, it finds 

 no valve or opening as does the cecropia and promethea. How- 

 ever, it masters the situation and gets out of its compact case 

 by wetting the cocoon with an acid liquid, which itsecretes in its 

 mouth for the purpose, and then pushes its way out between the 

 threads. It can be readily distinguished from all the other 

 moths, as it has what the children call "a window pane" in the 

 middle of each wing. This transparent spot consists of thin 

 membrane; in the hind wing it is the " eye" of the large, decorative 

 eye-spot. 



