THE BEAVER. 141 
the places of those which were drowned or otherwise killed in the preceding 
migration. 
The Lemming feeds upon various vegetable substances, such as grass, 
reeds, and lichens, being often forced to seek the last-named plant beneath 
the snow, and to make occasional air-shafts to the surface. Even when en- 
gaged in their ordinary pursuits, and not excited by the migratorial instinct, 
they are obstinately savage creatures. Mr. Metcalfe describes them as 
swarming in the forest, sitting two or three on every stump, and biting the 
dogs’ noses as they came to investigate the character of the irritable little 
animals. If they happened to be in a pathway, they would not turn aside to 
permit a passenger to move by them, but boldly disputed the right of way, 
and uttered defiance in little sharp, squeaking barks. 
The colour of the Lemming is dark brownish black, mixed irregularly with 
a tawny hue upon the back, and fading into yellowish white upon the abdo- 
ee Its length is not quite six inches, the tail being only half an inch 
ong. 
THE common BEAVER has earned a world-wide reputation by the wonder- 
ful instinct which it displays, independently of its very great value in 
producing costly fur and perfume. 
This animal is found in the northern parts of Europe and Asia, but is found 
in the greatest profusion in North America. In days long gone by, the 
Beaver was an inhabitant of our own island. 
The Beaver lives in societies, varying considerably in number, and united 
together in the formation of works which may fairly be considered as belong- 
ing to the profession of the engineer. They prefer to make their habitations 
by small clear rivers and creeks, or close to large springs, although they 
sometimes take up their abode on the banks of lakes. 
Lest they should not have a sufficient depth of water in all weathers and 
at all seasons, the Beavers are in the habit of building veritable dams, for the 
purpose of raising the water to the required level. These dams are composed 
of tree-branches, mud, and stones, and, in order effectually to resist the action 
of the water, are about ten or twelve feet in thickness at the bottom, 
although they are only two feet or so wide at the summit. 
In forming the dam, the Beaver does not thrust the ends of the stakes 
into the bed of the river, as is often supposed, but lays them down horizon- 
tally, and keeps them in their place by heaping stones and mud upon them. 
The logs of which the dam is composed are about three feet in length, and 
vary extremely in thickness. Generally, they are about six or seven inches 
in diameter, but they have been known to measure no less than eighteen 
inches in diameter. An almost incredible number of these logs are required 
for the completion of one dam, as may be supposed from the fact that a 
single dam will sometimes be three hundred yards in length, ten or twelve 
feet thick at the bottom, and of a height varying according to the depth of 
water, 
Before employing the logs in this structure, the Beavers take care to 
separate the bark, which they carry away, and lay up for a winter store of 
food. 
Near the dams are built the beaver-houses or “lodges,” as they are termed ; 
edifices as remarkable in their way as that which has just been mentioned. 
They are chiefly composed of branches, moss, and mud, and will accommodate 
five or six Beavers together. The form of an ordinarily sized Beaver’s lodge 
is circular, and its cavity is about seven feet in diameter by three feet in 
height. The walls of this structure are extremely thick, so that the external 
measurement of the same lodges will be fifteen or twenty feet in diameter, 
and seven or eight feet in height. The roofs are all finished off with a thick 
