SQUIRRELS, BEAVERS, DORMICE, AND RATS 231 



skin. The short and flattened ears, which are very much con- 

 cealed in the long fur, are naked and scaly, like the tail. The 

 hind feet of the beaver are larger than the fore paws, and are 

 webbed. A characteristic of great interest (as revealing an 

 archaic trait in the beaver's construction) is the opening of the 

 anal and uro-genital passages of the female into a common outlet, 

 which, though shallow, gives the appearance externally of con- 

 ditions like that of the Monotremes. The hind feet have another 

 peculiarity, in that they carry a small additional claw on the 

 second toe. There are five toes on both front and hind feet. 

 The fur is composed of long, soft, fine hair, set very thickly ; 

 and the general colour is a deep chestnut or umber-brown all 

 over the upper surface of the body and head, fading into a gray 

 on the stomach and under parts. Beavers are large animals, 

 measuring as much as 3 J ft. from the tip of the nose to the 

 end of the tail. The number of mammas is four, and only three 

 to four young are produced in a litter. 



The habits of the beaver are so remarkable that it is one of 

 the world's typical mammals, adorning many an ancient story 

 of Northern Europe and North America. These creatures have 

 developed (perhaps more in North America than in Europe) a 

 habit of felling trees on the banks of streams so that they fall 

 athwart the water, and by means of their trunks, boughs, and 

 added brushwood (together with the debris and mud brought 

 down by the stream) form a dam which eventually turns the 

 rivulet into a pool. Often in the middle of this pool the 

 " lodge," or nest, of the beaver is placed. This is reached by 

 one or several tunnels made from the shore under the surface of 

 the water into the nest, which is, of course, above the surface. 

 The nest is covered by brushwood, and the interior is lined with 

 grass. This underground passage and the surface of the nest, 

 together with much of the work on the dams, is rendered imper- 

 vious to water by mud plastered on with the beaver's fore feet. 

 The construction of the dams is sometimes most elaborate, for 

 after cutting down the tree or trees which are selected for the 

 purpose, the trunks of these are stripped of boughs and cut into 



