WASPS AND BEES 85 



but simple hairs in many Hymenoptera carry 

 pollen, and certain parasitic bees, and the drones 

 which never collect this " bee-bread " are equally 

 provided with feathered hairs. Related to this 

 pollen-collecting habit and also to the building 

 up of a waxen comb certain modifications of the 

 third or last pair of legs are present in worker- 

 bees, whereas in wasps the third pair of legs 

 differs but little from the first or second pair and 

 like them are primarily used for walking. 



Bees are throughout their life vegetarians ; 

 both larva and adult are nourished on the pro- 

 ducts of the plant-world. Not so the wasp. 

 Here the worker-insect feeds the young with 

 animal nutriment ; chewed up spiders, insects and 

 pieces of flesh torn from larger carcases are 

 eagerly devoured by the grub-wasps hanging 

 head downwards in their papery cell. 



For here, again, is yet another distinction. 

 The comb of the wasp is of a rough, coarse, paper- 

 like material, not secreted by the body of the 

 worker, but gnawed by the jaws or mandibles 

 off some park-palings or other dried wood and 

 kneaded up with some of the secretions of the 

 glands in the head until it forms a paste. When 

 dried, this paste looks like a dirty greyish coarse 



