23 
an opportunity as is possible, in confinement, of watching the 
habits of these animals,—the rough, dome-shaped structure of 
mud and sticks on the island being the far-famed Beaver hut, 
built by these animals themselves out of the natural materials. 
In a state of nature these huts are generally built on a small 
stream where the Beaver have constructed a dam, deepening 
the water sufficiently to keep the water from freezing to the 
bottom, so that they can get out under the ice during the win¬ 
ter. Most of their work is done during the night, but towards 
the hour in the afternoon when they are accustomed to be fed 
they may often be seen swimming about the pond and disap¬ 
pearing with a flap of the tail as they get within diving dis¬ 
tance of the entrance to the hut. 
They have done very well in their present quarters, and 
have bred there several times. Their food is purely vegetable, 
consisting mostly of the bark of trees and the roots of aquatic 
plants. They formerly ranged over the whole of North Amer¬ 
ica, but have long since been exterminated in the Southern, 
and in great part in the Middle and Eastern States. 
No. 5.—THE BEAR PITS. 
But three well-marked species of bears are believed to exist 
in North America—the Grizzly Bear ( Ursus horribilis ) ; the 
Black Bear (Ursus americanus'), with its constant variety 
{cinnamomeus) ; and the Polar Bear (Ursus maritimus )— 
though the variations of both the Grizzly and the Common 
Bear have given rise from time to time to supposed new species. 
The Grizzly ranges from the Yellowstone Valley and the upper 
Missouri to California, and south-west into Mexico,—those 
from the western slope of the Rocky Mountains being some¬ 
what darker in color and reaching a larger size than those to 
the eastward. 
The Black Bear is found almost all over the country, to¬ 
gether with what is called the Brown Bear, which is merely an 
ill-defined variety of the former species,—the black of the 
hair, in some individuals, turning to brown shortly after the 
1 yearly change of coat. The true Brown Bear is the Ursus 
arctos of northern Europe and Asia—an animal which pre¬ 
sents many points of likeness, and is perhaps identical with 
our Grizzly. The Cinnamon Bear is confined to the western 
parts of the United States. 
