THE CATERPILLAR AND THE MOTH 



to times when our ancestors lived as individuals irre- 

 sponsible one to another. 



The tent caterpillars ordinarily shed their skins six 

 times during their lives. At each molt the skin splits 

 along the middle of the back on the first three body seg- 

 ments and around the back of the head. It is then 

 pushed off over the rear end of the body, usually in one 

 piece, though most other caterpillars cast off the head 

 covering separate from the skin of the body in all molts 

 but the last. The moltings take place in the tent, except 

 the molt of the caterpillar to the pupa, and each molt 

 renders the caterpillars inactive for the greater part of 

 two days. When most of them shed their skins at the 

 same time there results an abrupt cessation of activity in 

 the colony. By the time the caterpillars reach maturity 

 the discarded skins in a tent outnumber the caterpillars 

 five to one. 



The first stage ot the caterpillars, as already described 

 (Fig. 144 D), suggests nothing of the color pattern of the 

 later stages, but in Stage II the spots and stripes of the 

 mature caterpillars begin to be formed. In succeeding 

 stages the characters become more and more like those of 

 the sixth or last stage (Plate 14 D, Fig. 148), when the 

 colors are most intensified and their pattern best defined. 

 Particularly striking now are the velvety black head with 

 the gray collar behind; the black shield of the first seg- 

 ment split with a medium zone of brown; the white stripe 

 down the middle of the back; the large black lateral 

 blotches, each inclosing a spot of silvery bluish white; the 

 distinctly bluish color between and below the blotches; 

 and the hump on the eleventh segment, where the median 

 white line is almost obliterated by the crowding of the 

 black from the sides. Yet the creatures wearing all this 

 lavishness ot decoration make no ostentatious show, for the 

 colors are all nicely subdued beneath the long reddish- 

 brown hairs that clothe the body. In the last stage, the 

 average full-grown caterpillar is about two inches long, 



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