4 THE LIFE-STORY OF INSECTS [CH. 



larva 1 (fig. 1 b, c, d) called a caterpillar, offering in 

 many superficial features a marked contrast to its 

 parent. Except on the head, whose surface is hard 

 and firm, the caterpillar's cuticle is as a rule thin 

 and flexible, though it may carry a protective arma- 

 ture of closely set hairs, or strong sharp spines. The 

 feelers (fig. 3 At) are very short and the eyes are 

 small and simple. In connection with the mouth, 

 there are present in front of the maxillae a pair of 

 mandibles (fig. 3Mn), strong jaws, adapted for biting 

 solid food, which are absent from the adult butterfly, 

 though well developed in cockroaches, dragon-flies, 

 beetles, and many other insects. The three pairs of 

 legs on the segments of the thorax are relatively 

 short, and as many as five segments of the abdomen 

 may carry short cylindrical limbs or pro-legs, which 

 assist the clinging habits and worm-like locomotion 

 of the caterpillar. No trace of wings is visible ex- 

 ternally. The caterpillar, therefore, differs markedly 

 from its parent in its outward structure, in its mode 

 of progression, and in its manner of feeding ; for 

 while the butterfly sucks nectar or other liquid food, 

 the caterpillar bites up and devours solid vegetable 

 substances, such as the leaves of herbs or trees. It 

 is well-known that between the close of its larval 

 life and its attainment of perfection as a butterfly, 



1 The term larva is applied to any young animal which differs 

 markedly from its parent. 



