EXTINCTION OF THE MAMMOTH—NEUVILLE. 831 
called attention to the nature of these facts as it appears in the 
light of anatomo-pathological comparisons, which alone, it seems 
to me, permit an understanding of its meaning; the skin of the ele- 
phant forms a vast corneous papilloma, which first appeared, ac- 
cording to all likelihood, as the result of the action of the irritants ® 
inherent in the environment in which the elephants live, and favored 
by a special character common to elephants and to the mammoth, 
namely, the absence of cutaneous glands. I have been no more able 
than earlier authors to find either sweat glands or sebaceous glands. 
There is no reason to believe that the degeneration of the hairy 
covering in the elephants has been accompanied by or even could 
have been caused by the previous disappearance of the sebaceous 
glands, whose presence is regarded as connected, except in very 
rare instances, with that of the hair, so much so that these glands 
are even regarded as appendages to the hair. On the mammoth, as 
well as on the elephant, the hair occurs without its accustomed annex, 
the sebaceous gland, and if the hair of the present-day elephants is 
very Sparse it was, on the contrary, as highly developed as pos- 
sible in the mammoth. Hence, there is no relation here between 
the diminution of the hairy covering and the disappearance of the 
sebaceous glands. For further details on this entire question. I refer 
to the two notes mentioned above. 
We have, therefore, two animals very nearly related zoologically— 
the mammoth and the elephant—one of which lived in severe climates 
while the other is now confined to certain parts of the Torrid Zone. 
The mammoth, it is said, was protected from the cold by its fur 
and by the thickness of its dermis. But the dermis, as I have said, 
and as the illustrations prove, is identical in the two instances; it 
would therefore be hard to attribute a specially adaptive function to 
the skin of the mammoth. The fur, much more dense, it is true, on 
the mammoths than on any of the living elephants, nevertheless is 
present only in a very special condition which is fundamentally 
® The forehead, the anterior part of the trunk, and the lower part of the legs show this 
character in a specially accentuated condition. But these are the parts which are the 
most exposed to blows and friction against trees and brush. It is by pressing with their 
forehead that elephants overcome the resistance of obstacles which the trunk can not put 
aside ; it is the anterior part of the trunk which comes the most directly in contact with 
the brush; as to the lower part of the legs the causes of irritation are yet more evident; 
finally the tail, where the papillary hypertrophy is especially strong and where it even 
takes on special characters, is constantly in motion and is thus subjected to irritative 
influences to which it reacts like the skin in general but with the acquisition of still more 
accentuated characters. Adaptation is here not an empty word; we know its causes, 
irritative influences; we can perceive its nature, keratosic reactions; we can watch the 
appearance of the special characters which it produces, papillomatous tendencies; we can 
observe its progress, graduated according to the use to which each region of the body is 
put and according to the influences which act on each region; finally it is easy to realize 
how useful to animals whose skin is fundamentally very sensitive the hypertrophy of the 
corneous layer can be, a hypertrophy which in other animals is pathological but which has 
here become normal, furnishing a protection which aids in the preseryation of the species. 
