Chap. VII. 
CELLS OF THE HIVE-BEE. 
233 
the adjoining cells has been built. This capacity in 
bees of laying down under certain circumstances a 
rough wall in its proper place between two just-com- 
inenced cells, is important, as it bears on a fact, which 
seems at first quite subversive of the foregoing theory; 
namely, that the cells on the extreme margin of wasp- 
combs are sometimes strictly hexagonal; but I have not 
space here to enter on this subject. Nor does there 
seem to me any great difficulty in a single insect (as in 
the case of a queen-wasp) making hexagonal cells, if 
she work alternately on the inside and outside of two 
or three cells commenced at the same time, always 
standing at the proper relative distance from the parts 
of the cells just begun, sweeping spheres or cylinders, 
and building up intermediate planes. It is even conceiv¬ 
able that an insect might, by fixing on a point at which 
to commence a cell, and then moving outside, first to 
one point, and then to five other points, at the proper 
relative distances from the central point and from each 
other, strike the planes of intersection, and so make an 
isolated hexagon: but I am not aware that any such 
case has been observed; nor would any good be derived 
from a single hexagon being built, as in its construction 
more materials would be required than for a cylinder. 
As natural selection acts only by the accumulation of 
slight modifications of structure or instinct, each profit¬ 
able to the individual under its conditions of life, it may 
reasonably be asked, how a long and graduated succession 
of modified architectural instincts, all tending towards the 
present perfect plan of construction, could have profited 
the progenitors of the hive-bee ? I think the answer is 
not difficult: it is known that bees are often hard pressed 
to get sufficient nectar; and I am informed by Mr. 
Tegetmeier that it has been experimentally found that 
no less than from twelve to fifteen pounds of dry sugar 
