The Evolution of Parental Care 39 



eggs on stones or aquatic plants or bury them in 

 gelatinous masses in the sand, but they certainly 

 have not the least glimmer of an idea concerning the 

 free swimming larvse to which the eggs will give 

 rise. The cabbage butterfly instinctively deposits 

 its eggs on cabbages or other cruciferous plants, the 

 hot fly oviposits upon the hairs of horses and cattle, 

 and the May fly drops its eggs into a pond or stream, 

 but it is utterly out of the question to suppose that 

 any of these creatures has the remotest notion of 

 the larvse that will issue from its eggs, much less 

 of the relation of the environment of the eggs to 

 the needs of larval life. 



A further step in the direction of parental care 

 is taken by the solitary wasps. In many species the 

 female digs a hole and then goes in search of a par- 

 ticular kind of insect or spider to serve as food for 

 her young grub. The victim is stung in such a way 

 that it is paralyzed but not killed, so that the young 

 can live upon food that is not decayed. Then the 

 prey is stored in the hole, an egg laid upon it, and 

 the hole filled up with dirt and left, the mother never 

 coming back to see how things fare with her young, 

 nor concerning herself further with its welfare. 

 In fact, most of these wasps never see their own 

 progeny, and show no signs of recognition when the 

 larvae are shown to them. All the wonderful in- 

 stinctive acts by which the solitary wasps provide so 

 well for the needs of their larvae are blindly per- 

 formed, and give no indication of any feeling of pa- 



