f this deplorable
accident happened she would not be able to get back again. It seems to
me that the effect is here taken for the cause, and that the falling
off of feathers and torpidity must be the result rather than the
motive of cloistration. One is tempted to believe that the male
desires by this method to guarantee his female and her offspring
against the attacks of squirrels or rapacious birds.

_Hygienic measures of Bees._--Among the animals who expend industry on
hygiene and the protection of their dwellings, we must place Bees in
the first line. It may happen that mice, snakes, and moths may find
their way into a hive. Assaulted by the swarm, and riddled with
stings, they die without being able to escape. These great corpses
cannot be dragged out by the Hymenoptera, and their putrefaction
threatens to cause disease. To remedy this scourge the insects
immediately cover them with _propolis_--that is to say, the paste
which they manufacture from the resin of poplars, birches, and pines.
The corpse thus sheltered from contact with the air does not putrefy.
In other respects Bees are very careful about the cleanliness of their
dwellings; they remove with care and throw outside dust, mud, and
sawdust which may be found there. Bees are careful also not to defile
their hives with excrement, as Kirby noted; they go aside to expel
their excretions, and in winter, when prevented by extreme cold or the
closing of the hive from going out for this purpose, their bodies
become so swollen from retention of faeces that when at last able to go
out they fall to the ground and perish. Buechner records the
observations of a friend of his during a season in which a severe
epidemic of dysentery had broken out among the bees, which interfered
with the usual habits of the insects; on careful examination of a hive
it was found that a cavity in the posterior wall of the hive,
containing crumbled clay, had been used as an earth closet. Many
mammals are equally careful in this respect; thus, for example, the
Beaver, as Hearne observed, always enters the water, or goes out on
the ice, to urinate or defaecate; the faeces float and are soon
disintegrated.

Animals are also careful about aeration. Thus, among Bees, in a hive
full of very active insects the heat rises considerably and the air is
vitiated. A service for aeration is organised. Bees ranged in files
one above the other in the interior agitate their wings with a
feverish movemen