HOW TO KNOW THE BUTTERFLIES 



In the caterpillar state the division of the 

 body into three regions is not so well marked as 

 it is with the adult butterfly. The head is always 

 distinct ; following the head there are thirteen 

 comparatively similar segments, which constitute 

 the thorax and the abdomen. The first three seg- 

 ments following the head form the thorax of the 

 adult insect ; each of these segments bears a pair 

 of legs, which develop into the legs of the adult. 

 The remaining ten segments constitute the ab- 

 domen. On the lower side of the abdomen there 

 are five pairs of fleshy appendages, which are 

 known as the prolegs ; these are borne by the 

 third to the sixth and the last abdominal seer- 

 ments. Each proleg is armed at the tip with a 

 series of hooks by which it clings to the object 

 upon which the caterpillar is walking, When a 

 caterpillar changes to a chrysalis the prolegs are 

 lost, being shed with the last larval skin. 



The larvae of butterflies differ greatly in re- 

 spect to the clothing of the body ; some are ap- 

 parently naked, the few hairs with which the 

 body is clothed being inconspicuous (see Plate 

 XI, Fig. 2) ; with others the hairs are more 

 numerous and larger (Plate IV, Fig. 1) ; and 

 still others are clothed with large spines (Plate 

 XXV, Fig. 2). 



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