THE LIFE OF MAMMALS 
In America our beaver seems to have dwelt everywhere that 
suitable woods grew and waters ran, from northern Florida and 
the mountains of Mexico, northward as far as birch and willow 
trees grow. As for one hundred and fifty years its fur has been 
one of the most highly valued spoils of the trapper, and only 
recently, and in the more civilized parts of the continent, has 
its getting been at all restricted by law, it is not strange to learn 
that the animal survives only in a few isolated colonies east of 
the northern Rockies and south of the Canadian wilderness. 
That any are left is due, probably, more to the disuse, half a 
century ago, of its fur in hat making, following the invention 
of silk hats, than to anything else. Even now fifteen to twenty 
thousand skins a year are collected by the Hudson Bay and 
other fur companies, which, however, are now taking precau- 
tions against diminution of the supply by setting apart certain 
islands in northern Canada as preserves. 
The beaver is the largest of the rodents except the capybara, 
is about two feet long, without the tail, and weighs thirty to 
thirty-five pounds. As it is a dweller in cold waters, it has an 
exceedingly fine, close fur, with a dense under fleece and a thick 
skin which, when stripped off, forms an almost round mat. Its 
hind feet are webbed and are powerful swimmers, while the 
fore feet are small and as handy as those of a squirrel. The 
great yellow chisels of the front teeth are always sharp, and the 
tail is a most interesting organ; it is about a foot long, very 
strong, and expands into a flattened, oval mass of fatty tissue, 
clothed in a lustrous black horny skin that looks as if scaled. 
This remarkable tail has been called a trowel, and has been described 
as used to spread and pat the mud plastered upon the dams and lodges; 
also that it serves as a sledge which the other beavers load, and thus haul 
earth and stone. In reality, it is of great service in swimming and div- 
ing, and the loud slap it may give as an alarmed beaver dives acts as 
an effective signal of danger; but it takes no part in the constructive 
work. The food of the beaver is wholly vegetable, and mainly the bark 
of deciduous trees, especially birch, poplar, and maple — never of ever- 
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