28 SECRETS OF ANIMAL LIFE 



the social evolution of wasps is illustrated by some 

 of the Diggers and Pompilids, where the mother 

 makes for her larvae a larder of paralyzed victims, 

 but has no further commerce with her brood. She 

 quickly makes a store of preserved (indeed, living) 

 flesh and has done with it. The second chapter 

 is seen in some African Eumenid-wasps, in which 

 the mother brings freshly-paralyzed victims from 

 day to day as her hatched larva has need of them. 

 There is more of a personal touch here, for the 

 mother comes into intimate relations with her off- 

 spring, and seems to know it as hers. The 

 third chapter shows an abandonment of the paralyz- 

 ing device, the poison not being used except in 

 killing the naturally recalcitrant victims. The 

 prey is more or less masticated into pap, the mother 

 retaining a tithe for herself, and the result is laid 

 beside the larva, whose mouth, it is very interest- 

 ing to notice, has ceased to have much power of 

 chewing. 



But some very curious features now come to 

 light, that the salivary secretion of the larva be- 

 comes greatly exaggerated, as sometimes happens 

 in man; that it tends to overflow at the mouth; 

 and that it is for the mother " 1'objet d'une recherche 

 particuliere." It is the sop that keeps the mother- 

 wasp self-forgetful, corresponding to the look in a 

 baby's eyes that keeps a human mother from utter 

 weariness. The nurture of a single larva, distributed 

 over a considerable time, leaves the mother-wasp 

 with the gift of leisure, and there are gradations 



