226 THE ORIGIN OF SPECIES 



a cell. It was most interesting to observe 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 scalloped 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, rectangular piece of 

 wax, a thin and narrow, knife-edged ridge, colored 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 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 un- 

 gnawed, were situated, as far as the eye could judge, exactly along 

 the planes of imaginary intersection between the basins on the 

 opposite side of the ridge of wax. In some parts, only small por- 

 tions, in other parts, large portions of a rhombic plate were thus 

 left between the opposed basins, but the work, from the unnat- 

 ural state of things, had not been neatly performed. The bees 

 must have worked at very nearly the same rate in circularly gnaw- 

 ing 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, while 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 working at exactly the same rate from the opposite sides; for I 

 have noticed half-completed rhombs at the base of a just com- 

 menced cell, which were slightly concave on one side, where I sup- 

 pose that the bees had excavated too quickly, and convex on the 



