INSECTA, CONTINUED 



207 



the winter in this stage but usually eggs are 

 deposited in the spring and partly develop 

 that same season. 



The egg does not hatch into a form at all 

 resembling the adult, but instead, there 

 emerges a tiny worm-like form called the 

 larva, which differs entirely in structure, 

 having no wings, nor compound eyes, but 

 possessing several extra pairs of legs and 

 biting mouth parts. In fact, these and 

 other insect larvae are what we often call 

 " worms," which they do somewhat resem- 

 ble in shape. However, they are really one 

 step in the development of an insect, and 

 are vastly more complex than the true 

 worms. The larval stage devotes its whole 

 attention to eating, growing, and moulting, 

 and after about five changes of clothing, 

 it stops this gluttonous life in which it 

 often does a great deal of 

 harm, and goes into a 

 resting stage called the 

 pupa. 



In butterflies, when the 

 last moult occurs, a pupa 

 case or chrysalis is formed 

 which protects the insect 

 during its long pause. The 

 larva often seeks a pro- 

 tected spot or burrows in 

 the earth before this 

 change occurs. The moth 

 larva, on the other hand, 

 spins a wonderful case of 

 silk, the cocoon, by which 

 it protects and attaches its pupa for its period of retirement. 



FIG. 66. Sphinx moth, showing pro- 

 boscis; at left the proboscis is shown coiled 

 up on the under side of the head, the nor- 

 mal position when not in use. Large figure, 

 one-half natural size; small figure, natural 

 size. From Kellogg. 



