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 intelligence, 
what is it ike? An inconspicuous creature which 
resembles something between a large rat and a 
squirrel, 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 
