BEAVERS AND THEIR WAYS. 271 
In point of size, coloration, and general habits, it may be 
said that no material difference can be detected externally 
between the two forms, but there appears to be a peculiarity in 
the skull, which is sufficiently constant to warrant specific 
separation. This peculiarity lies in the relative length of the 
nasal bones, which occupy one-third of the length of the skull. 
If a transverse line be drawn across the base of the nasal bones, 
it will be found that this line in the European Beaver intersects 
the orbits, while in the American Beaver it usually intersects the 
antorbital processes. The latter species, then, is distinguishable 
by its shorter and slightly broader nasal bones. 
The prevailing colour of the Beaver’s fur is reddish brown; 
rarely black ; still more rarely white or particoloured. Hearne 
states that in the course of twenty years’ experience in the 
countries about Hudson’s Bay, though he travelled 600 miles to 
the west of the sea coast, he never saw but one white Beaver 
skin, and that had many reddish and brown hairs along the 
ridge of the back, the flanks being of a glossy silvery white.* 
Prince Maximilian states that white Beavers are occasionally 
found upon the Yellowstone River.t 
The habits of the European and American Beavers are so 
similar that a description of those of the one might apply to 
those of the other, although it is remarkable that in parts of 
Europe where the animal is threatened with extermination it 
has so far modified its habits as to avoid building huts or 
“lodges,” as they are termed, which would too readily betray its 
haunts, and prefers to live in holes in the river-bank (like a 
water vole), from which it is only expelled by the incoming water 
when the river rises, when it excavates a fresh cell at a higher 
level, and only as a last resource builds a hut upon the bank.t 
They frequently throw up dams across the streams frequented 
by them. These dams, which are destined to keep the water of 
variable streams up to the necessary height for the convenience 
of the Beaver, are wonderful pieces of work, and almost justify 
** Hearne’s Journey to the Northern Ocean,’ p. 241 (1796), 
} ‘Travels in North America,’ p. 332 (1843). 
{ It may be observed that the specific name fiber bestowed upon the 
European Beaver is derived from. Jibrum, denoting the edge or margin of 
the water wherein the animal loves to dwell, the generic name Castor being 
the Greek Kacrwp.—Herodotus, iv. 109; Aristotle, vili. 5, 8. 
