HOW TO KNOW THE BUTTERFLIES 



in one, the chrysalis hangs suspended by the tail 

 alone (Plate I, Fig. 3), in the other, the tail is 

 fastened in a similar manner, but there is also a 

 girth about the middle of the body (Plate III, 



Fi g- 3)- 



When a caterpillar is full-grown it stops eat- 

 ing and seeks a convenient place in which to 

 transform. It then spins, upon the object to 

 which it is to fasten itself, a button of silk, into 

 which it fastens the prolegs at the hind end of 

 the body. Plate II, Figure 1, represents a cater- 

 pillar which has done this and is ready to trans- 

 form ; and Plate III, Figure 2, represents another 

 caterpillar which has suspended itself by a button at 

 the tail and a girth about the middle of the body. 



After suspending itself, the caterpillar rests 

 for a time ; then its skin splits open in the 

 middle of the back, and the head end of the body 

 is worked out through this opening. Plate II, 

 Figure 2, represents one which was photographed 

 just as it reached this stage in the transformation. 

 As the shed skin dries it shrinks back toward 

 the tail, where it is attached to the button of 

 silk. Before the body is entirely freed from the 

 skin, the tail of the chrysalis, which is armed 

 with hooks, is withdrawn from it and firmly fast- 

 ened to the button of silk. 



24 



