174 ZOOLOGY. 



such a preliminary work is not required. The beavers 

 separate into a certain number of families, and commence 

 constructing their huts, or repairing those already built. 



Fig. 128. The Beaver. 



These cabins are raised against the dyke or on the edge 

 of the waters, and are of an oval form ; they are constructed 

 in the same way as the dyke itself, of branches of trees, 

 strongly cemented together by a kind of puddle- work. For 

 this purpose they use the earth dug from under the wall or 

 the banks, and work it with their feet ; it does not appear 

 that the tail is employed for this purpose. The branches of 

 the trees, no matter what be their size, are readily cut through 

 with their sharp rodent teeth ; and when a larger trunk is 

 required so as to intercept the stream, they, working in 

 groups, divide it so that it shall fall int the most favourable 

 manner to be floated to its destined resting-place. Their 

 cabins have two floors, one under water, the other above ; the 

 entrance and exit are by the chamber which is under water. 

 Finally, all these works are carried on at night, and with 

 extreme rapidity. When the proximity of man hinders the 

 beaver from uniting in numbers sufficient to carry on those 

 works requiring the association of many, they no longer 

 build huts ; but the instinct of construction remains even in 

 captivity, as has been seen in beavers confined in the Garden 



