THE BEAVERS OF NORTH AMERICA 77 



the making of canals and roadways. Nothing 

 seems to be lacking in the chain of evidence. 

 And the animal that does all this wonderful 

 work and exhibits such extraordinary intelHgence, 

 what is it like ? An inconspicuous creature which 



Pembles something between a large rat and a 

 lirrel, weighing up to sixty-five or seventy 

 pounds, about forty-five inches long when fully 

 grown. The tail is thick, flat and closely-covered 

 on both sides with small modified scales, 'the ears 

 are short, dark and round covered with incon- 

 spicuous short hair, the front teeth are long, 

 curved and extremely sharp and strong. The body 

 is covered with thick fur and hair of a general dark 

 brown running into chestnut and greys. The legs 

 are short and the front feet are small and more 

 like hands, while the hind ones are long, broad, 

 and completely webbed, thoroughly adapted to the 

 animals' aquatic habits. This gives a general idea 

 of the beavers' appearance, a fuller description of 

 which will be found in another chapter. In 

 swimming only the hind feet are used, the great 

 spread of which enables the animal to maintain a 

 surprising speed whether at the surface, or below 

 water, where it can stay for eight or nine minutes 

 without fresh air. The tail is employed to a very 

 limited extent, its principal use being as a rudder. 

 I have never been able to make absolutely sure 

 that it is employed as a propeller, though I have 

 watched beaver swimming on every available 



