150 THE UNIVERSE. 



storms. The mother has paid for her child-birth 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 hungry 

 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. 



Live prey is imperatively necessary for some larvae ; they 

 require it so soon as they are born, and as the mother can- 

 not fetter it to their cradle, she poisons it. But more in- 

 genious than Locusta, she only administers as much poison 

 as is necessary to stupefy or paralyze it, so that the young 

 insect, when it issues from the egg, finds near it the dying 

 insect, which it ends by devouring. This is the case with 

 many of the Sphex species. The fly places one of its eggs 

 at the bottom of a little hole which it makes in the ground ; 

 it then goes out to hunt till it discovers a spider or a cater- 

 pillar ; and so soon as it finds one, it stings it scientifically, 

 and bears it quite paralyzed to its nest. 



Finally, having placed its victim close to its egg, the 

 Sphex closes the opening of the subterranean hollow with 

 a little stone, and takes wing, giving it no further heed. 

 Nothing more remains for maternal tenderness to do. 



Some ichneumons, or vibrating flies, are much more rapa- 

 cious and bold. The larvse of some of these, though ex- 

 tremely small, nevertheless attack large caterpillars, fix 

 upon their bodies, and gnaw away till death ensues. The 

 mother, by the aid of her boring instrument, pierces the 



