XIX THE RETURN TO THE NEST 265 



return. However, it came, and with its invariable 

 precision alighted quite close to its doorway, whose 

 look I had changed for the fourth time, having 

 covered the site with a large mosaic of pebbles the 

 size of a nut. My work, which, compared to the Bem- 

 bex, surpassed what for us are the Megalithic monu- 

 ments of Brittany, or the lines of Menhirs at Carnac, 

 was powerless to deceive the mutilated insect. 

 Though deprived of antennae it found the entrance 

 in the midst of my mosaic as easily as would have 

 done an insect under other conditions. This time I 

 let the faithful mother go home in peace. 



The site transformed four times over, the out- 

 works of the abode changed in colour, scent, and 

 material, the pain of a double wound, — all failed to 

 disconcert the Hymenopteron or even to make her 

 doubtful as to the precise locality of her doorway. 

 I had exhausted my stratagems, and understood less 

 than ever how the insect, if it have no special guide 

 in some faculty unknown to us, can find its way 

 when sight and smell are baffled by the artifices of 

 which I have spoken. Some days later an ex- 

 perience gave me the opportunity to take up the 

 problem from a new point of view. The Bembex 

 burrow had to be bared in its whole extent, without 

 quite destroying it, to which operation its shallow- 

 ness and almost horizontal direction, and the light 

 soil in which it was made, lent themselves readily. 

 The sand was gradually scraped off with the blade 

 of a knife, and thus, deprived of roof from end to 

 end, the underground abode became a semi-canal 

 or conduit, straight or curved, some eight inches 

 long, open where was the entrance, and ending 



