

154 THE INSECT WORLD. 
legs belonging to the first pair of membranous legs. Our cater- 
pillar begins by fixing on this point a thread, which is the first 
of those that are intended to tie it up securely. 
“This thread,” says the illustrious author of the “Mémoires 
pour I’Histoire des Insectes,” “must pass over the caterpillar’s 
body, and be attached by its other end near the leg corresponding 
to that near which the first end was fastened. To spin the 
thread the proper length, and at the same time to fix it in its 




big. 108.—Caterpillars of the Cabbage Buttertly (Pieris brassice). 
proper place, the caterpillar has only to bring round its head to 
the fifth segment. The thread will be drawn from the spinning 
apparatus as the head advances over half the circumference of 
the circle which it has to describe; and when it has described this, 
there will only remain for it to stick fast the second end of the 
thread against the support. Thus the head, which was atfirst placed 
against one of the legs, advances little by little on the outline | 
of the fifth ring as far as to its middle (Fig. 108). It is the 
facility the caterpillar has of reversing its body that enables it to 
make its head perform this journey ; in proportion as it moves 
it over the circumference of the ring, it twists its body. And at 
last, when it has brought it over the top of the segment, its body is 
exactly folded in two; it draws it little by little from this situation 
by bending towards the other side, and by causing its head to pass 
