212 ROMANCE OF THE. BEAVER 
foliated hard enamel, the inside of the folds being 
filled with soft dentine, which wears away and 
leaves the ridges sharp and capable of grinding 
wood or bark to a fine pulp. All the teeth grow 
continually to. make up for the natural wear. In 
case a tooth is injured or broken the opposite one 
grows to abnormal length, frequently to the great 
discomfiture of the animal. . The folds of hard 
enamel continue with little change of form down 
to the base of the teeth, but the semi-hard dentine 
is only formed near the grinding surface. The 
young beaver is born with well-developed teeth, 
which differ only in point. of size from those of 
the adult. 
The brain of the heiver is nitiveably. smooth 
and lacking in the corrugations which are supposed 
to indicate intelligence. It seems peculiar that an 
animal which has so much (from our standard of 
comparison) to signify inferiority should, by its 
works, prove itself to be so highly intelligent. 
Romanes says: “There is no animal—not even 
excepting the ants and bees—whose instinct has 
risen to a higher level of far-reaching adaptation 
to certain constant conditions of environment, or 
whose faculties, undoubtedly instinctive, are more 
puzzlingly wrought up with faculties no less 
undoubtedly intelligent.” 
The beaver’s coat is composed, like that of 
nearly all fur-bearing animals, of fur and hair. In 
the beaver it is thick, woolly, brown fur about 
