Chap. Vill. Cell-making Instinct. 223 



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 exca- 

 vated to the same depth as in the former experiment, 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 appeared to me that the bees do not always succeed in work- 

 ing at exactly the same rate from the opposite sides ; for I have 

 noticed half-completed rhombs at the base of a just-commenced cell, 

 which were slightly concave on one side, where I suppose that the 

 bees had excavated too quickly, and convex on the opposed side 

 where the bees had worked less quickly. In one well marked 

 instance, I put the comb back into the hive, and allowed the bees 

 to go on working for a short time, and again examined the cell, and 

 I found that the rhombic plate had been completed, and had become 

 perfectly flat : it was absolutely impossible, from the extreme thin- 

 ness of the little plate, that they could have effected this by gnawing 

 away the convex side ; and I suspect that the bees in such cases 

 stand on opposite sides and push and bend the ductile and warm 

 wax (which as I have tried is easily done) into its proper inter- 

 mediate plane, and thus flatten it. 



From the experiment of the ridge of vermilion wax we can see 

 that, if the bees were to build for themselves a thin wall of wax, 

 they could make their cells of the proper shape, by standing at the 

 proper distance from each other, by excavating at the same rate, 



