Parasites 



incessantly a few inches above the sandy ex- 

 panse. For hours at a time, on the same spot, 

 after the manner of the Scolia-wasp he 

 spies the coming of the females out of 

 the ground. If our watch be patient 

 and persevering, we shall see the mother, 

 after trotting about for a bit, stop some- 

 where and begin to scratch and dig, finally 

 laying bare a subterranean gallery, of 

 which there was nothing to betray the en- 

 trance ; but she can discern what is invisible to 

 us. She penetrates into the abode, remains 

 there for a while and at last reappears to re- 

 place the rubbish and close the door as it was 

 at the start. The abominable deed is done: 

 the Mutilla's egg has been laid in another's 

 cocoon, beside the slumbering larva on which 

 the new-born grub will feed. 



Here are others, all aglitter with metallic 

 gleams : gold, emerald, blue and purple. They 

 are the humming-birds of the insect-world, 

 the Chi7sis-wasps or Golden Wasps, another 

 set of exterminators of the larvae overcome 

 with lethargy in their cocoons. In them, the 

 atrocious assassin of cradled children lies 

 hidden under the splendour of the garb. One 

 of them, half emerald and half pale-pink, 

 193 



