228 
INSTINCT. 
Chap. VII. 
modifications of instincts in themselves not very won¬ 
derful^—hardly more wonderful than those which guide 
a bird to make its nest,—I believe that the hive-bee 
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 (^. 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 fiat walls 
of wax on the lines of intersection between the basins, 
so that each hexagonal prism was built upon the scal¬ 
loped 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- 
