XXII AN EXCHANGE OF NESTS 311 



with eight chambers, was at first considerably em- 

 barrassed. Which of the eight was the right one ? — 

 in which was her heap of bee bread ? She plunged 

 down into each room, and at length found what she 

 was seeking — a condition like that which she had left 

 when she took her last journey, the beginning of a 

 store of food. From that moment she behaved like 

 her neighbour, and carried honey and pollen to a cell 

 not made by her. 



Let us restore the nests to their natural places, 

 exchanging them afresh. Each bee, after a little 

 hesitation, sufficiently explained by the very great 

 difference between the two nests, will work alternately 

 in her own cell and the strange one. At length the 

 egg is laid and the cell closed, whichever the nest 

 may be that she is occupied with at the moment when 

 the provisions are sufficient. Such facts show clearly 

 why I hesitate to give the name of memory to the 

 singular faculty that brings back the insect so 

 accurately to the site of her nest, yet does not allow 

 her to distinguish her work from that of another, 

 however great may be the difference of appearance 

 between them. 



Now let us experiment on Chalicodoma muraria 

 from another psychological point of view. Here is a 

 mason bee at work on the first course of her cell ; in 

 exchange I give her one not only completed, but half 

 full of honey, which I stole from an owner who would 

 speedily have laid an egg there. What will the 

 mason do with this munificent gift which spares 

 her the labour of building and storage ? Leave her 

 mortar, of course, lay an egg, and close all up. Not 

 at all ! the animal finds our logic illogical. The insect 



