The Life-History and Anatomy of Butterflies 



caterpillar is crawling about from place to place. The larva 

 appears to guide itself in great part by means of the palpi. 



The body of the caterpillar is covered by a thin skin, which 

 often lies in wrinkled folds, admitting of great freedom of 

 motion. The body is composed, as we have seen, of rings, or 

 segments, the first three of which, back of the head, correspond 



Fig. 15.— Head 

 of caterpillar of 

 Anqsia plexip- 

 pus, side view, 

 showing ocelli- 



-Caterpillar of Anosia plexippi* 

 butterfly (Riley). 



milkweed 



to the thorax of the perfect insect, and the last nine to the abdomen 

 of the butterfly. On each ring, with the exception of the second, 

 the third, and the last, there is found on either side a small oval 

 opening known as a spiracle, through which the creature breathes. 

 As a rule, the spiracles of the first and eleventh rings are larger in 

 size than the others. 



Every caterpillar has on each of the first three segments a pair 

 of legs, which are organs composed of three somewhat horny 

 parts covered and bound together with skin, and armed at their 

 extremities by a sharp claw (Fig. 17). These three pairs of feet 

 in the caterpillar are always known as the fore legs, and corre- 



Fig. 17. — Fore 

 leg of caterpil- 

 lar of Vanes- 

 sa antiopa,en- 

 larged. 



Fig. 18. — Ante- 

 rior segments of cat- 

 erpillar of milkweed 

 butterfly, showing 

 thoracic or true legs 

 (Riley). 



Fig. 19. — Proleg 

 of caterpillar of 

 Vanessa antiopa, 

 enlarged. 



spond to the six which are found in the butterfly or the moth. 

 In addition, in most cases, we find four pairs of prolegs on 

 the under side of the segments from the sixth to the ninth, 

 and another pair on the last segment, which latter pair are 



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