XII THE IGNORANCE OF INSTINCT 171 



of a knife, take away the materials which block it, 

 and entirely restore the communication of the cell 

 with the outer air. Then, without injuring the 

 edifice, I draw the ephippiger out of the cell where it 

 is lying with its head to the far end, and its ovi- 

 positor to the entrance. The egg is as usual on its 

 breast, near the base of one of the hind legs — a proof 

 that the Sphex had given her last touch to the 

 burrow, and would never return. These dispositions 

 made, and the ephippiger placed safely in a box, 

 I gave up my place to the Sphex, who had been 

 watching while her domicile was rifled. Finding 

 the entrance open, she entered and remained some 

 moments, then came forth and took up her work 

 where I interrupted it, beginning to stop the en- 

 trance conscientiously, sweeping the dust backward, 

 and transporting sand grains to build them with 

 minute care, as if doing a useful work. The orifice 

 being again thoroughly blocked, she brushed herself, 

 seemed to give a glance of satisfaction a't her work, 

 and finally flew off. 



Yet she must have known that the burrow was 

 empty, since she had gone inside, and made pro- 

 longed stay, but yet after this visit to the plundered 

 dwelling, she set to work to close it with as much 

 care as if nothing had happened. Did she propose 

 to turn it later to account, returning with a fresh 

 prey, and laying a new egg ? In that case the 

 burrow was closed to defend it from indiscreet 

 visitors while the Sphex was away. Or it was a 

 measure of prudence against other miners who 

 might covet a ready-made chamber, or a wise pre- 

 caution against internal wear and tear, and, in fact. 



