“ They live in burrows on the banks of rivers, like the water-rat, and show little of the architectural instinct so conspicuous in the American form; but this may be owing to unfavorable external conditions rather than to want of the faculty, for there is a well-authenticated instance of a colony of beavers, on a small stream near Magdeburg, whose habitations and dam were exactly similar to those found in America.” In Siberia they still exist in considerable numbers, though their pelts do not now figure largely in the export of furs, and there the animal is inclined to erect lodges and dams. ”

“ This perfection of beaver economy is by no means seen everywhere, but might commonly be observed previous to 1850 in such highly favorable regions as the swampy forests about the headwaters of the Mississippi, and it is being renewed in northern Maine, where, under the protection of law, beavers are increasing and reoccupying their ancient haunts. ”

“ Meanwhile, from the first summer onward, the gradually increasing number of beaver families have built each for itself permanent homes, known from their resemblance to the Algonkian wigwam as ‘lodges.’ The sites chosen are along the banks of the stream or canal, and several houses may be so close together as to touch, or they may be widely scattered. The larger lodges are, in the interior, about 7 feet in diameter, and between 2 and 3 feet high, with the floor and inner walls made smooth by gnawing and wear. ”

“ This structure, like the dam, is formed of branches of trees, matted with mud, grass, moss, and other material. The walls are very thick, and the entire structure not only secures much warmth, but is an efficient protection from wolves, wolverines, and other beasts of prey, especially when solidly frozen in winter. Each family builds, maintains, and occupies its own lodge, the current belief that several families live together arising from the fact that the young beavers usually continue to live with their parents until the third year. ”

“ Economic Considerations.—Beavers are closely related to the squirrels, and, like them, ‘sit up’ a great deal, holding their food up to their mouths in their fore paws, which otherwise are used very dexterously. It is needless to contradict the many foolish stories as to the use of the tail as a vehicle for carrying mud, a trowel for applying it, and so on. The animals live well in confinement, and colonies are nourishing in zoölogical gardens and parks in New York, Washington, and other American cities, as well as abroad, where small, watered valleys, fenced with wire, are devoted to them. ”

“ The beaver is usually at least 2 feet in length from the nose to the root of the tail, and weighs about 35 pounds, and the tail is about 10 inches in length. These dimensions are sometimes exceeded. The general form of the animal is thick and clumsy, broadest at the hips and squirrel-like. The body terminates in a thick oval tail, flattened transversely, about twice as long as broad, and naked of hairs, the surface being covered with plates of black, indurated skin, resembling horn-scales. The fore limbs are small and squirrel-like, the hinder ones large and powerful. Each foot has 5 toes ”

“ They dwell normally in colonies along streams, which may have been inhabited for scores of generations, and whose improvements represent the combined labor of thousands of individuals past and present. Such a colony begins by the settlement in the spring upon some sluggish, moderately deep woodland stream or pond of a pair of young beavers, who have emigrated thither from some old colony. Their first labor is to dig a burrow in the bank, the entrance to which is at a safe depth beneath the water, and the interior chamber at a safe height above its normal rise. ”

“ The beavers work at the dam only at night, except in an emergency, and each one does what it thinks proper in a quite independent way, though the result is for common benefit. After many years such dams may be 4 or 5 feet high at the channel, and stretch to the right and left across low ground for 50 yards or more, converting the space above it into a broad, grassy pond, having a network of clear channels. ”

“ Such a dam grows constantly by the addition of all sorts of material—not only the logs and sticks from which the bark has been gnawed for food, but others cut for the purpose, and a constant intermixture of roots and branches with stones, moss, grasses, and mud. ”

“ Its extraordinary powers of gnawing are exerted to cut down trees several inches in diameter, both for food and for the construction of those houses and dams which have rendered it so much an object of admiration to mankind. ”

“ The impossibility of obtaining this food in winter, when the waters and woods are clogged with ice and snow, compels them to prepare a supply. For this purpose the beavers become very active in the autumn, each family cutting down large trees and gnawing their limbs and trunks into sections small enough to be dragged to the water and floated to the neighborhood of their lodge. ”

“ These canals are kept open with great pains, while the rest of the pond becomes gradually grown up with grass, and they form avenues along which lodges and burrows are placed, and where the colony may swim freely, and float their food and building materials from the woods to their lodges and dams, of which latter, on a long-tenanted and favorable stream, several may exist. ”

“ In a flat country the mere raising of the water by flooding spaces of woods answers the purpose to some extent; but this is most intelligently supplemented by the animals, who dig deep canals, 2 or 3 feet wide, which penetrate the woods in various directions, sometimes for 100 yards or more, and thus render accessible a large number of trees otherwise out of reach. ”

“ Food and Winter Provision.—The food of beavers is almost wholly the bark of deciduous trees, especially poplar, birch, willow, linden, and maple; they never eat ‘evergreen’ bark, and are absent from forests exclusively coniferous. In the summer they gnaw at fresh bark day by day, and also eat more or less of lily-roots and other green vegetables, berries, and leaves. ”

“ They are formed in front of hard, orange-colored enamel, while the back of the tooth is formed of a softer substance, more easily worn down, so that a sharp, chisel-like edge is always preserved; the bulbs being also persistent, so that the teeth are continually growing as they are worn away. ”

“ In closer captivity they betray their constructive instincts by weaving the sticks supplied them into the bars of their cages. They have usually four young at a birth, and keep them at home for two years. ”

“ Community Life and Architecture.—The architectural operations and coöperative life of these animals are very wonderful, although the statement, at one time commonly made, that beavers drive stakes into the ground, has no foundation in fact ”