GROWTH OF INSECTS. 83 



True worms, however, never change into any thing else. 

 Such, for example, is the earthworm, hair-worm, and leech, 

 and worms which live in the sea. 



FIG. 82. EAETIIWOBH. 



FIG. 83. MABINE WOEM. 



These worms, and other true worms, generally speaking, 

 have the body divided into a great many segments or rings, 

 as in the earthworm. In the larvae of insects, on the con- 

 trary, the segments are limited in number. "With few ex- 

 ceptions the larvae of insects have legs, and these legs in the 

 fore-part of the body are jointed. In worms, jointed legs do 

 not occur. The jointed legs of the larvae number three pairs, 

 and are on the three successive rings back of the head, and 

 consequently correspond to the three pairs of legs in the adult 

 insect. 



In certain larvae other legs occur, but these are not jointed, 



though often having special structures at their extremities, 

 5 



