Chap. VIIL] CELL-MAKING INSTINCT. 347 



I then put into the hive, instead of a thick, rectangu- 

 lar 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 

 time; so that the basins, as soon as they had been a little 

 deepened, came to have flat bases; and these flat bases, 

 formed by thin little plates of the vermilion wax left 

 ungnawed, were situated, as far as the eye could judge, 

 exactly along the planes of imaginary intersection 

 between the basins on the opposite sides of the ridge of 

 wax. In some parts, only small portions, in other parts, 

 large portions of a rhombic plate were thus left between 

 the opposed basins, but the work, from the unnatural 

 state of things, had not been neatly performed. The 

 bees must have worked at very nearly the same rate in 

 circularly gnawing away and deepening the basins on 

 both sides of the ridge of vermilion wax, in order to 

 have thus succeeded in leaving flat plates between the 

 basins, by stopping work at the planes of intersection. 



Considering how flexible thin wax is, I do not see 

 that there is any difficulty in the bees, whilst at work on 

 the two sides of a strip of wax, perceiving when they 

 have gnawed the wax away to the proper thinness, and 

 then stopping their work. In ordinary combs it has ap- 

 peared to me that the bees do not always succeed in 

 working at exactly the same rate from the opposite 

 sides; for I have noticed half-completed rhombs at the 



