HYALOPHORA PROMETHEA. 137 



fine light yellowish brown silk, extending this coat- 

 ing, with great skill and foresight, over the footstalk 

 of the leaf, and attaching it firmly to the branch, so 

 as to secure the leaf from being separated by any 

 accident. This preliminary operation having been 

 accomplished, the caterpillar next draws the edges 

 of the leaf together ; thus forming a perfect external 

 covering or mantle, in which it spins a fine strong 

 durable cocoon of fine silk. In this habitation our 

 little architect passes the winter, secure from birds 

 and other enemies. (This is attempted to be repre- 

 sented in the upper right-hand figure of Plate XII.) 

 As soon as the cocoon has been completed, the 

 caterpillar again sheds its skin, and is transformed 

 into a pupa or nymph, as represented in the par- 

 tially opened cocoon figured in Plate XII. fig. 2. At 

 first, the leaf enveloping the cocoon remains green, 

 but soon changes to a red or brown colour, when it 

 becomes brittle, and is gradually carried away by 

 the winds and storms of the winter, until finally 

 nothing remains except the cocoon itself, which is 

 firmly suspended by the silk which once covered 

 the footstalk of the leaf. The instinct of the cater- 

 pillar, in thus providing for the permanent attach- 

 ment of its future habitation, appears to be superior 

 to that shown by many other species. 



" The caterpillar is of a delicate green colour, 

 with yellow feet ; each segment of the body, except 

 the posterior, is marked with six blue spots, from 

 which arise small black tubercles; in the second 

 and third segments, however, the two centre tuber- 



