The teeth of the beavers are sharp and powerful, and their jaws possess an extraordinary amount of strength.  This enables them to bite through wood, tear the bark from trees, and chew vegetable substances of all sorts.  During summer they regale themselves on fruits and plants of various descriptions; but their winter stock of food consists of the bark of the birch, plane, and other trees--and even of the young wood itself, which they steep in water before devouring it.