370 
A JOURNEY UNDER DIFFICULTIES. 
not only serves this animal as a means of defense, but also for dig- 
ging up roots and thus procuring food. 
The horn which projects from the nose of the rhinoceros is a 
very remarkable structure, and worthy of a brief notice. It is in 
no way connected with the skull, but is simply a growth from the 
skin, and may take rank with hairs, spines, or quills, being indeed 
formed after a similar manner. If a rhinoceros horn be exam¬ 
ined—the species of its owner is quite immaterial—it will be seen 
to be polished and smooth at the tip, but rough and split into numer¬ 
ous filaments at the base. 
GLOW WITH ALL COLORS OF THE RAINBOW. 
These filaments, which have a very close resemblance to those 
which terminate the plates of whale-bone, can be stripped upwards 
for some length, and if the substance of the horn be cut across, it 
will be seen to be composed of a vast number of hairy filaments 
lying side by side, which, when submitted to the microscope, and 
illuminated by polarized light, glow with all the colors of the rain¬ 
bow, and bear a strong- resemblance to transverse sections of actual 
hair. At the birth of the young animal, the horn is hardly visible, 
and its full growth is the work of years. 
As the horn is employed as a weapon of offense, and is sub¬ 
jected to violent concussion, it is set upon the head in such a manner 
as to save the brain from the injurious effects which might resuU 
from its use in attack or combat. In the first place, the horn has no 
direct connection with the skull, as it is simply set upon the skin, 
and can be removed by passing a sharp knife around its base, and 
separating it from the hide on which it grows. 
In the second place, the bones of the face are curiously devel¬ 
oped, so as to form an arch with one end free, the horn being placed 
upon the crown of the bony arch, so as to diminish the force of the 
concussion in the best imaginable manner. The substance of the 
horn is very dense, and even when it is quite dry, it possesses very 
great weight in proportion to its size. In former days, it was sup¬ 
posed to bear an antipathy to poison, and to cause effervescence 
whenever liquid poison was poured upon it. 
