CAPTURE OF ANIMALS. 43 



with their entrances under water, and their huts in front of 

 them. These are called Bank Beavers, though they differ in 

 nothing from their dam-building brethren. Those that live 

 on small streams, where there is not water enough to surround 

 their huts and protect their stores from freezing in winter, 

 build dams to raise the water and create ponds suitable for 

 their purpose. They commence by cutting down with their 

 teeth trees of all sizes, from those of ten inches in diameter 

 to the smallest brushwood. These are cut into pieces suitable 

 for transportation by a single animal, and then are conveyed 

 to the place chosen for a dam, the Beaver laying one paw over 

 the timber, as he drags it along with his teeth. The smaller 

 materials, such as mud, sticks, and stones, are carried between 

 one of the fore-paws and the chin. The dams differ in shape 

 according to the nature of the stream where they are built. 

 In streams where the current is rapid or powerful, the dams 

 are built with a convex curve up-stream, which strengthens 

 them against the floods and the ordinary constant pressure of 

 the stream. In streams where the water has but little mo- 

 tion, the dams are built straight across ; and sometimes they 

 have been observed with a curve down-stream. No special 

 order or method is observed in building the dams, except that 

 the work is carried on with a regular sweep, and all the parts 

 are made of equal strength. They are frequently six or eight 

 feet high, and from ten to thirty rods in length. The trees, 

 resting on the bottom, are so mixed and filled in with mud, 

 sticks, stones, leaves, and grass, that very little water escapes, 

 except by running over the top ; and the height is so uniform 

 that the water drips evenly from one end to the other. After 

 the dams are built, but before they are frozen over, the Bea- 

 vers lay in their winter stores, which consist of the bark of 

 the willow, aspen, poplar, birch, and alder. They fell these 

 trees with their teeth, cut them up into short sections, and 

 sink them in the water near their huts. In the winter, when 

 their ponds are frozen over, they enter the water by the holes 

 at the bottom of their huts, collect these sunken trees and 

 take them to their dwellings, as they require them for food. 

 The breeding season of the Beaver commences in April or 



