162 



THE UNIVERSE. 



it heaps them up m a httle pile, and when its body is quite 

 cleared out, and only resembles a hollow bladder, the female 



99. Caterpillar, Chrysalis, and Butterfly, male and female, of the Pine Silk-worm Moth— 



Bomhyx dispar. 



straightway covers its progeny with it, attaches the edges 

 round them, and dies directly after; thus forming for 

 them a convex, solid roof, the impermeability of which 

 protects its eggs against the injurious agency of the air and 

 storms. The mother has paid for her childbirth with her 

 life, and her young are born under the shelter of her 

 mummified corpse. 



Some insects are guided in another way by maternal 

 instinct. Instead of sacrificing themselves, they kill other 

 animals in order to minister to the wants of their hungrj' 

 offspring. As each species requires a peculiar food, it is 

 only by the aid of various processes that the parents suc- 

 ceed in procuring it for them. 



