NATURAL HISTORY. 
pyramid in shape. The size of the crushing or molar teeth is very distinctive of the Gorilla when it 
is compared with the other great man-like Apes, for the upper ones are equal in size, and in the lower 
jaw the hindmost tooth is larger than the others. Moreover, these lower teeth have five cusps or pro- 
jections. There is a ridge extending obliquely across the crowns of the lower molars from an inner 
to an outer cusp ; and the cross-like grooves of the upper surface of the corresponding teeth in man 
are not seen. The manner in which the teeth of the Gorilla differ from those of other Apes will be 
mentioned in the several descriptions. Milk teeth, or those of the first set, are found in baby and 
young Gorillas, and when they fall out the permanent set come out of the jaw and replace them, 
adding also to their numbers. The long canine teeth are characteristic of the old males, and those of 
the females and young are much smaller. The thirty-two teeth of the Gorilla, eminently adapted for 
a mixed vegetable diet, arc therefore arranged as follows : — Upper jaw — four incisors, two canines, 
four pre-molars, and six true molars, and there is the same number in the lower jaw. 
It is a very remarkable fact, and one which will be of some interest in comparing one of the other 
great Apes with the Gorilla, that the skull of the young Gorilla (of both sexes) and that of the full- 
grown female differs materially from that of the male in the absence of the prominent ridges of the 
top and back of the head. This gives a roundness to their skulls which would at first sight lead to 
the belief that they could not belong to the same species. 
Living upon such nice things as sugar-canes and pine-apples, the Gorilla has a long and well- 
formed tongue to taste them with,* and a good nose to enjoy their scent and fragrance. The 
nostrils are open, and look downwards, being separated by a moderately wide piece of flesh covering, 
gristle, or cartilage, and they are protected above by very dense bones, which form the slight ridges 
called the nasal bones. Up the nose a passage leads to the air spaces in the bone of the front 
of the head, and they and some curiously curled bones not very far from the nostrils are covered 
with a delicate membrane well supplied with the nerves in which the function of smell exists. 
Both the natives and Du Chaillu allude to the roaring and yelling of the old male Gorillas, 
and it will be noticed further on that the young ones can make noise enough. Dr. Savage was 
told that when the male is first seen he gives a terrific yell that resounds far and near through 
the forest, something like Kh — ah! Kh — ah, prolonged and shrill, and others have compared the 
noise to distant thunder. They have an organ of voice on the top of the windpipe, made on the 
plan of that of man, but deficient in many respects, and especially in those fine adaptations of 
structure which produce the human voice. But there is a very remarkable 
arrangement in their larynx, as it is called, which, although it has nothing 
to do with the formation of sound, may possibly make it more resonant 
and growling, and this is one of the things which separate the great Ape 
from man in matters of mere construction. 
At the back of our tongues, and also of those of the Gorilla, is a little 
flap, rather hard and gristly in us, and only membranous and soft in the Ape, 
which covers over the top of the air-passage into the windpipe when any food 
is swallowed. The food or drink would otherwise get into the air-passage, and 
would be constantly going “ the wrong way.” Immediately under this flap, 
or, as it is called, the epiglottis, is a space limited in front by the hard 
substance we call in our throat the “Adam’s apple,” and at the bottom of it 
are the movable structures by whose action voice is produced. Now, in the 
Gorilla, this space is not shut in front as it is in us, but there are two 
openings in it, one on either side, which lead to a complicated sac or pouch. 
This pouch is made of thin membrane, and covers, when blown out like a 
bag — for the air coming out of the windpipe can be forced in — the front of the windpipe, and 
projects sideways under the muscles of the throat, and even amidst those of the armpits. The 
Gorilla can thus blow his neck out, as it were, and when he is yelling, the air in the bag 
* The tongue has the same kind of papilla?, or slight projections of its surface, as in man ; some called fungiform 
are seen at the tip, and on the surface generally, and others more or less cup-sliaped. These last are found at the back, 
and are not arranged in any definite shape or order. 
