'H 5 
CHAPTER XXL 
SOCIAL HABITATIONS . 
SOCIAL MAMMALIA. 
The Beaver — Its form and aquatic habits — Need for water and means used 1 to* 
procure it — Quadrupedal engineering — The dam of the Beaver — Erroneous 
ideas of the dam — How the Beaver cuts timber — The Beaver in the Zoologi- 
cal Gardens — Theories respecting the Beaver’s dam — How the timber is 
fastened together — Form of the dam, and mode of its enlargement — Beaver- 
dams and coral-reefs — The house or lodge of the Beaver — Its locality and 
structure — Use of a subterranean passage — How Beavers are hunted — 
Curious Superstition — ‘ Les Paresseux.’ 
We now come to the Social Habitations, and give precedence 
to those which are constructed by Mammalia, 
Of the Social Mammalia, the Beaver ( Castor fiber ) takes the 
first rank, and is the best possible type of that group. There 
are other social animals, such as the various marmots and others ; 
but these creatures live independently of each other, and are 
only drawn together by the attraction of some favourable locality. 
The Beavers, on the other hand, are not only social by dwelling 
near each other, but by joining in a work which is intended for 
the benefit of the community. 
The form of the Beaver is sufficiently marked to indicate that 
it is a water-loving creature, and that it is a better swimmer 
than walker. The dense, close, woolly fur, defended by a 
coating of long hairs, the broad, paddle-like tail, and the well- 
webbed feet, are characteristics which are at once intelligible. 
Water, indeed, seems to be an absolute necessity for the Beaver, 
and it is of the utmost importance to the animal that the stream 
near which it lives, should not be dry. In order to avert 
such a misfortune, the Beaver is gifted with an instinct which 
teaches it how to keep the water always at or about the same 
