the hive is known mainly to depend on a
large number of bees being supported. Hence the saving of wax by largely
saving honey must be a most important element of success in any family
of bees. Of course the success of any species of bee may be dependent
on the number of its parasites or other enemies, or on quite distinct
causes, and so be altogether independent of the quantity of honey which
the bees could collect. But let us suppose that this latter circumstance
determined, as it probably often does determine, the numbers of a
humble-bee which could exist in a country; and let us further suppose
that the community lived throughout the winter, and consequently
required a store of honey: there can in this case be no doubt that it
would be an advantage to our humble-bee, if a slight modification of
her instinct led her to make her waxen cells near together, so as to
intersect a little; for a wall in common even to two adjoining cells,
would save some little wax. Hence it would continually be more and more
advantageous to our humble-bee, if she were to make her cells more and
more regular, nearer together, and aggregated into a mass, like the
cells of the Melipona; for in this case a large part of the bounding
surface of each cell would serve to bound other cells, and much wax
would be saved. Again, from the same cause, it would be advantageous to
the Melipona, if she were to make her cells closer together, and more
regular in every way than at present; for then, as we have seen, the
spherical surfaces would wholly disappear, and would all be replaced by
plane surfaces; and the Melipona would make a comb as perfect as that of
the hive-bee. Beyond this stage of perfection in architecture, natural
selection could not lead; for the comb of the hive-bee, as far as we can
see, is absolutely perfect in economising wax.

Thus, as I believe, the most wonderful of all known instincts, that
of the hive-bee, can be explained by natural selection having taken
advantage of numerous, successive, slight modifications of simpler
instincts; natural selection having by slow degrees, more and more
perfectly, led the bees to sweep equal spheres at a given distance from
each other in a double layer, and to build up and excavate the wax along
the planes of intersection. The bees, of course, no more knowing that
they swept their spheres at one particular distance from each other,
than they know what are the several angles of the hexagonal prisms