228 INSTINCT. Chap. VII. 



has acquired, through natural selection, her inimitable 

 architectural powers. 



But this theory can be tested by experiment. Follow- 

 ing the example of Mr. Tegetmeier, I separated two 

 combs, and put between them a long, thick, square strip 

 of wax : the bees instantly began to excavate minute 

 circular pits in it; and as they deepened these little 

 pits, they made them wider and wider until they were 

 converted into shallow basins, appearing to the eye per- 

 fectly true or parts of a sphere, and of about the dia- 

 meter of a cell. It was most interesting to me to ob- 

 serve that wherever several bees had begun to excavate 

 these basins near together, they had begun their work 

 at such a distance from each other, that by the time the 

 basins had acquired the above stated width (i. e. about 

 the width of an ordinary cell), and were in depth about 

 one sixth of the diameter of the sphere of which they 

 formed a part, the rims of the basins intersected or 

 broke into each other. As soon as this occurred, the 

 bees ceased to excavate, and began to build up flat walls 

 of wax on the lines of intersection between the basins, 

 so that each hexagonal prism was built upon the fes- 

 tooned edge of a smooth basin, instead of on the straight 

 edges of a three-sided pyramid as in the case of ordinary 

 cells. 



I then put into the hive, instead of a thick, square 

 piece of wax, a thin and narrow, knife-edged ridge, 

 coloured with vermilion. The bees instantly began on 

 both sides to excavate little basins near to each other, in 

 the same way as before ; but the ridge of wax was so 

 thin, that the bottoms of the basins, if they had been 

 excavated to the same depth as in the former experi- 

 ment, would have broken into each other from the 

 opposite sides. The bees, however, did not suffer this 

 to happen, and they stopped their excavations in due 



