bee persists in using big
Snail-shells just as though her ancestors had never known the danger of
the Osmia-blocked vestibule. Once these facts are duly recognized, the
conclusion is irresistible: it is obvious that, as the insect does not
hand down the casual modification tending towards the avoidance of
what is to its disadvantage, neither does it hand down the modification
leading to the adoption of what is to its advantage. However lively the
impression made upon the mother, the accidental leaves no trace in the
offspring. Chance plays no part in the genesis of the instincts.

Next to these tenants of the Snail-shells we have two other Resin-bees
who never come to the shells for a cabin for their nests. They are
Anthidium quadrilobum, LEP., and A. Latreillii, LEP., both exceedingly
uncommon in my district. If we meet them very rarely, however, this may
well be due to the difficulty of seeing them; for they lead extremely
solitary and wary lives. A warm nook under some stone or other; the
deserted streets of an Ant-hill in a sun-baked bank; a Beetle's vacant
burrow a few inches below the ground; in short, a cavity of some
sort, perhaps arranged by the Bee's own care: these are the only
establishments which I know them to occupy. And here, with no other
shelter than the cover of the refuge, they build a mass of cells joined
together and grouped into a sphere, which, in the case of the Four-lobed
Resin-bee, attains the size of a man's fist and, in that of Latreille's
Resin-bee, the size of a small apple.

At first sight, we remain very uncertain as to the nature of the strange
ball. It is brown, rather hard, slightly sticky, with a bituminous
smell. Outside are encrusted a few bits of gravel, particles of earth,
heads of large-sized Ants. This cannibal trophy is not a sign of
barbarous customs: the Bee does not decapitate Ants to adorn her hut.
An inlayer, like her colleagues of the Snail-shell, she gathers any hard
granule near at hand capable of strengthening her work; and the dried
skulls of Ants, which are frequent around about her abode, are in her
eyes building-stones of equal value to the pebbles. One and all employ
whatever they can find without much seeking. The inhabitant of the
shell, in order to construct her barricade, makes shift with the dry
excrement of the nearest Snail; the denizen of the flat stones and of
the roadside banks frequented by the Ants does what she can with the
heads of the defunct and,