BEAVERS. IOI 
longer, and move about much less than at other times. In the winter, in America 
at all events, they swim about beneath the ice, dragging up water-lily roots for 
food and feasting upon the store of branches they have accumulated in the deep 
pools during the winter; and it is for the purpose of securing a sufficient depth of 
water in which to swim beneath the ice that they construct their well-known 
dams. Most of the beavers still remaining in the rivers of the Old World live in 
burrows in the banks, without constructing either dams or lodges. The colony 
near Magdeburg, alluded to above, are known, however, to have undertaken both 
these engineering works; and it is hence probable that European beavers were 
originally similar as regards their habits to their American cousins, but that 
through their reduced numbers and the constant persecution which they have 
undergone, the building propensity has been lost. 
In America beavers generally select as their haunts a well-timbered district 
traversed by a narrow stream; and by felling the trees on the banks, and forming 
with the aid of their trunks and boughs a dam and lodges across the stream, the 
water is headed back so as to form a large lake or pool. In some cases a series of 
such dams and pools may be seen one above another in the course of the stream. 
It is believed that the original object of tree-felling is to obtain a supply of food 
for winter; and that the employment of the peeled trunks and branches for the 
construction of the dam and lodges is a secondary development. The beaver 
fells the trees it requires by gnawing through their stems with its sharp front 
teeth at a short distance above the ground; the stem being generally gnawed 
nearly equally all round till the tree falls with its own weight. As trees on a river 
bank generally incline towards the water, they usually fall in the required direction. 
Sometimes, however, the animals miscalculate, and trees which they have felled 
may be seen caught in the forks of neighbouring stems. The trees selected for 
felling are usually from five to eight or nine inches in diameter, but occasionally 
trunks of as much as eighteen across are successfully attacked. The beaver 
goes to work in a thoroughly scientific manner, gnawing out very large chips, 
which are sometimes as much as nine inches in length. When the trees are felled, 
they are stripped of their boughs, and the trunks cut into lengths of five or six feet, 
which, after being barked, are rolled into the stream or pond, and employed in the 
construction of the dam and lodges. 
The term “lodge,” it may be explained, is applied in America to the abodes 
constructed by these animals in the water of their ponds. It is now generally 
accepted that the lodge is nothing more than an extreme development of the burrows 
or “wash” in the banks. On this subject Mr. Martin writes as follows: “Starting 
with the simple burrow, the next step is the accumulation of logs and branches 
about its entrance, forming what is called a ‘bank-lodge. In places where the 
water is shallow towards the shore, a great advantage would be derived from ex- 
tending this artificial covering of brushwood, so that in time a natural evolution 
of the lodge disconnected entirely from the shore would take place, and form an 
independent and very convenient refuge from landward enemies.” The lodge con- 
tains a large internal chamber, lined with grass, and is entered by several 
approaches beneath the surface of the water. The construction of the lodge is, 
however, of a much less elaborate nature than has often been stated to be the case. 
