CHAP. V.- 



'HE TRANSFORMATIONS OF INSECTS. 



27 



spins a layer of silk upon some object, and then crawls upon 

 it and fastens the hooks at the tips of its legs into the silk ; it 

 now remains quiet for a short time, when the skin on its back 

 soon splits open, and the included caterpillar then crawls out. 

 This operation is repeated at intervals three or four times, 

 until the caterpillar reaches its full size (Fig. 78). It next 



Tig. 78. 





spins a bunch of silk to the under side of some object, and 

 in this it entangles the hooks at the tips of its hind legs ; 

 then letting go its hold it hangs suspended, with the head and 

 fore part of the body drawn slightly upward, giving to the 

 body somewhat the form of the letter J (Fig. 79, ). In a short 



Fig. 79 



time the skin on its back splits open, and the included object, 

 by elongating its body, pushes' the fore part of the latter 

 through the rent in the skin; the body is then contracted, or 

 shortened, thus drawing the old skin backward ; and this 

 operation is repeated until the skin is worked back to, and 

 covering only, the last two or three segments (Fig. 79, b). The 

 pupa is attached, near the hind end of its body, to the old 



