colonies on the banks of streams or
deep lakes, and construct dwellings which are very well arranged. In
their methods we find combined the woven shelter with the house of
built earth. Their cabins are established over the highest level of
the water and look like little domes. In building them the animals
begin by placing reeds in the earth; these they interlace and weave so
as to form a sort of vertical mat. They plaster it externally with a
layer of mud, which is mixed by means of the paws and smoothed by the
tail. At the upper part of the hut the reeds are not pressed together
or covered with earth, so that the air may be renewed in the interior.
A dwelling of this kind, intended to house six or eight individuals
who have combined to build it, may measure up to 65 centimetres in
diameter. There is no door directly opening on to the ground. A
subterranean gallery starts from the floor and opens out beneath the
water. It presents secondary branches, some horizontal, through which
the animal goes in search of roots for food, while others descend
vertically to pits specially reserved for the disposal of ordure.

But it is, above all, the Beaver (_Castor fiber_) who exhibits the
highest qualities as an engineer and mason. This industrious and
sagacious Rodent is well adapted to inconvenience the partisans of
instinct as an entity, apart from intelligence, which renders animals
similar to machines and impels them to effect associated acts, without
themselves being able to understand them, and with a fatality and
determination from which they can under no circumstance escape.

Beavers now only live in Canada. A few individuals may, however, still
be found on the banks of the lower Rhone, in Camargue, and on a few
other European rivers. Several centuries ago they existed in the
neighbourhood of Paris in considerable numbers. The Bievre gained its
name from the old French word for Beaver, and its resemblance to the
English name, as well as to the German (_Biber_), is striking. In the
sixteenth century, according to Bishop Magnus of Upsala, the Beaver
was still common on the banks of the Rhine, the Danube, and on the
shores of the Black Sea, and in the North it still exercised great art
in its constructions. In the twelfth century it was found in Scotland
and Wales. If we go back to ancient times, we find that Herodotus
mentions that the Budini who lived in the neighbourhood of the Black
Sea used the skins of the Beavers, whi