io6 The Life-History of Insects 



insect with a pair of long-tail cercopods (fig. 6^). 

 Very many insects develop from campodeiform larvae ; 

 the grubs of numerous Beetles, of Stoneflies, May- 

 flies, Dragonflies and Lacewing flies all belong to 

 this type (67, 68). 



Eruciform Larvae. — No better example of the 

 second type of larva can be found than the cater- 

 pillar of a Moth (fig. 66). In many respects it con- 

 trasts strongly with the armoured, active, six-legged 

 beetle-grub. Except for the large head which is 

 completely chitinised, the short legs, and some hook- 

 lets, tubercles, or spines, the whole of the cylindrical 

 worm-like body is soft-skinned. As in the beetle- 

 grub, simple eyes only are present, and the feelers 



Fig. 66. — The Common Silkworm or Caterpillar of the Moth Bo7nbyx titori. 

 Natural size. From Riley, Bull. 9. Div. Ent. U.S. Dept. Agr. 



are very short. The head bears a pair of powerful 

 mandibles, by means of which the caterpillar devours 

 leaves \ in the moth it will be remembered these 

 jaws are reduced to the merest vestiges. The 

 maxillae of the first pair (which form the long 

 sucking-trunk of the moth) are, in the caterpillar, 

 small and inconspicuous organs; each consists of a 

 basal plate bearing two short, segmented processes — 

 the hood and the palp. The maxillae of the second 

 pair are fused together to form a plate-like lower 

 lip, and the tongue projects as a tubular spinneret 

 through which open the ducts of the silk-glands 

 (fig. 67). These glands are long paired tubes, 



