236 INSECTS INJUllIOUS TO VEGETATION. 



have two short, thread-like tails, the inner one the longest, and 

 tipped with white ; along the hind margin of these same wings 

 is a row of little pale blue spots, interrupted by a large orange- 

 red crescent enclosing a small black spot ; the wings benea^th 

 are slate-gray, with two wavy streaks of brown edged on one 

 side with white, and on the hind wings an orange-colored spot 

 near the hind angle, and a larger spot of the same color en- 

 closing a black dot just before the tails. It expands one inch 

 and one tenth. 



Some butterflies have the first pair of legs so much shorter 

 than the others, that they cannot be used in walking, and are 

 folded on the breast IDce a tippet. Their caterpillars, when 

 about to transform, do not make a loop to support the fore 

 part of the body, but suspend themselves vertically by the 

 hindmost feet. As they all secure themselves pretty much in 

 the same way, it may be proper to explain the process. Hav- 

 ing finished eating, the caterpillar wanders about till it has 

 discovered a suitable situation in which to pass through its 

 transformations. This may be the under side of a branch or 

 of a leaf, or any other horizontal object beneath which it can 

 find sufficient room for its future operations. Here it spins a 

 web or tuft of silk, fastening it securely to the surface beneath 

 which it is resting, entangles the hooks of its hindmost feet 

 among the threads, and then contracts its body and lets itself 

 drop so as to hang suspended by the hind feet alone, the head 

 and fore part of the body being curved upwards in the form of 

 a hook. After some hours, the skin over the bent part of the 

 body is rent, the fore part of the chrysalis protrudes from the 

 fissure, and, by a wriggling kind of motion, the caterpillar-skin 

 is slipped backwards till only the extremity of the chrysalis 

 remains attached to it. The chrysalis has now to release 

 itslPif entirely from the caterpillar-skin, which is gathered in 

 foid^T^round its tail, and to make itself fast to the silken tuft 

 by the* minute hooks with which the hinder extremity is 

 provided. Not having the assistance of a transverse loop to 

 support its body w^hile it disengages its tail, the attempt would 

 seem perilous in the extreme, if not impossible. Without 

 having witnessed the operation, we should suppose that the 



