98 



SUBKINGDOM VERTEBEATA. 



Fig. 162. 



Castor canadensis, American Beaver. 



Castoridae. The Beaver was once abundant in North 

 America, but it retires before civilization, and is fast becom- 

 ing extinct in this country as in Europe. Its scaly tail and 

 webbed hind feet enable it to swim with great ease. The 

 enamel of its incisors is very hard.* It is noted for its inge- 

 nuity in building its habitations.! 



* The Indians, before the introduction of iron among them, were accustomed to 

 use these as chisels for working wood and horn. A tame heaver will take an apple 

 in its forepaws, and, by desirously turning and pressing it against its incisors, paro 

 it as readily as if the work had been done with a knife. ( Wood.) 



| If the place chosen is by stagnant water, the beaver at once commences build- 

 ing on the bank, with lower entrances from the water ; but, if it is a running stream, 

 a large company combine to build a dam in order to keep the water at the same 

 level. Going up stream they gnaw off trees one to ten or more inches in diameter. 

 These they float down to the spot selected, and, laying them crosswise, fill in the 

 interstices with mud and stone, which they carry between their forepaws and chin. 

 When the water is high enough to prevent freezing to the bottom in winter, they 

 separate into small families, and build their houses against the dam or the adjoining 

 bank. The entrance is beneath the water, and the vaulted roof is well plastered with 

 a thick coat of earth, to protect against the Wolverine. When they dive they always 

 slap with their tail, and also when upon the tops of their houses inspecting them, or 

 about their work. This has given rise to the absurd idea of their using it for a 

 ti-owel to plaster their buildings, and as a hod to carry the mortar they are said to 

 prepare. They lay up food for winter by sinking logs and bark near their houses; 

 but in summer feed upon fjrass, fruits and roots. 



