CHAPTER XXL 



SOCIAL HABITATIONS. 



SOCIAL MAMMALIA. 



The Beaver — Its form and aquatic habits — Need for water and means used to 

 procure it — Quadrupedal engineering — The dam of the Beaver — Erroneous 

 ideas of the dam — How the Beaver cuts timher — The Beaver in the Zoological 

 Gardens — Theories respecting the Beaver's dam — How the timher is fastened 

 together — Form of the dam, and mode of its enlargemeut — 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 Beavek {Castor fher) 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 favoiu'able 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 suificiently 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 run 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 mark, or, at 

 all events, to prevent it from sinking below the requisite level. 



If any modern engineer were asked how to attain such an 

 object, he would probably point to the nearest water-mill, and 



