308 THE WASPS. 



therein by means of a long ovipositor, and thereby to obtain 

 sufficient nourishment for the hatched grubs. They most 

 frequently select the caterpillars of butterflies, which con- 

 tinue to live and to eat with the foreign guest in their bodies 

 until the parasite injures some vital part and becomes a 

 pupa. The mother, moreover, is not indifferent what young 

 she chooses for her posterity ; she also knows with marvel- 

 lous skill how to snatch a suitable opportunity, however 

 hidden it may be. Thomas Marsham (in Bingley, loc. cit. 

 iv., p. 134) observed in June, 1787, an ichneumon-fly on a 

 wooden post in Kensington Gardens. It was moving rapidly, 

 holding its antennae bent downwards. It felt about with 

 these until it discovered the hole of an insect. When this 

 was found it popped in its head and antennas, and waited 

 for about a minute in this position seeming very busy. The 

 hole was then examined with equal care from the other 

 side. The insect next turned round, measured the distance, 

 and inserted into the hole the long ovipositor at the end of 

 its abdomen. It remained in this situation for about two 

 minutes, drew out the ovipositor, flew round the 'hole, and 

 felt about in it again with its antennas for about a minute. 

 The ovipositor was then again introduced. The whole 

 operation was repeated three times, one after another, before 

 the eyes of the observer, but he approached too closely in 

 order to see more exactly, and the insect flew away. 



A week later Mr. Marsham saw several ichneumon-flies 

 at work at the same place. They were apparently driving 

 their ovipositors half their length into the firm wood, a thing 

 that seemed impossible. But more exact investigation 

 showed that the boring was made each time into the middle 

 of a small white spot which consisted of fine white sand, and 

 was a hole made by the Apis maxillosa (a species of bee) 

 within which was a young bee larva. In very deep unclosed 

 holes the creature sometimes crawled backwards so far that 

 only its head, two fore-legs and wings, outstretched like arms, 

 were visible. Mr. Marsham often saw the fly leave the hole 

 again after investigating it, clearly because it had found it 

 empty. 



The fact that the solitary insects do not reach the high 

 grade of intelligence and ingenuity evinced by their social 

 relations, living in ordered communities, may easily be 

 explained by the influence of the society itself, and by the 



