AIR POUCHES OF ORANG.(After Temminck.)BRAIN OF ORANG.(From Royal College of Surgeons.)
AIR POUCHES OF ORANG.(After Temminck.)
AIR POUCHES OF ORANG.(After Temminck.)
BRAIN OF ORANG.(From Royal College of Surgeons.)
BRAIN OF ORANG.(From Royal College of Surgeons.)
Moreover, besides these causes of growth there are those hidden ones which refer to sex, the old males acquiring a hideous aspect in our eyes, but lovely in those of the more comely female Miases, from the growth of long head ridges and the curious face pads. The bulk of the brain of an Orang is about one-half of that of a man of ordinary mind; and the brain itself, whilst it is higher in measurement than that of any of the Apes already mentioned, is long and flat in comparison with that of man. In front it tapers off slightly, and is not flat in front and below, for there the eye-cases or orbits, by projecting upwards, render the brain in their neighbourhood, as it were, excavated. As in the other Apes, the back of the brain is well developed, and the several parts distinguishable in man exist. One of the furrows so visible in the Troglodytes, which marks the side of the brain towards the back (the occipito-temporal), is scarcely in existence in the Orang.
There is something very human in the appearance of the brain case in the young of both species of Orang. The back and sides have the peculiar “bumpy” look of those of the child; there are then no crests, and the brow ridges, extremely small, merge into a straightish forehead. The face looks long in front of the eyes, or orbits, and these are elliptical or oval, and approaching the circular in outline.The cheeks look wide even in the young ones; and it will be noticed that the bone of the upper jaw (superior maxillary bone) has a short projection, which joins the molar or cheek-bone at some distance from the jaw. There is a hole or holes under the orbit in man and in the Troglodytes which transmits a nerve to the face, and people who have tic-douloureux know where it is very well; this is close to the junction of the molar and jaw-bones in the Troglodytes, but in the Orang this junction is much further off the middle of the face. This causes the extra width to the cheeks. The bone there forms the surface upon which the curious pad of fat and skin rests, which gives such an ugly look to the face in the old ones, when all these parts have grown to excess. The young have milk teeth, and in the upper jaw the last crushing or molar tooth has large cusps behind and projecting inwards, and the incisor teeth are equal in size. In the lower jaw the incisors are grooved in front in a curious manner; and the great molar teeth with five cusps have a curiously wrinkled-looking surface. Underneath the skull looks long, and the hole for the spinal cord is much longer than broad, and the joints or condyles are distant from the front of it. The palate is broad and the nose cavity also, and there is a bony styloid process connected with the ear-bone.
WRIST BONES OF ORANG.[17]
WRIST BONES OF ORANG.[17]
In the female of theSimia morio, which is the smallest Orang, all the structures just mentioned as characterising the youngSimia satyrusand the young maleMorioare exaggerated. There are faint frontal ridges also, and the back ridge or crest is shown, but there is hardly any difference in the size of the brain case. The front bone of the upper jaw is very distinct; and the creature whose skull is in the British Museum had its permanent teeth, the milk ones having fallen. There was the same number of teeth as in the Troglodytes and in man. But it is in the old males that the juvenile structures are greatly altered; and it is indeed hard to believe their skulls ever could have belonged to the same species. In the old males the brain case has not increased in its capacity, but it is furnished with huge ridges along the front and crossing behind. The ridges commence on the brow ridges and the outside of the orbits, which are no longer nearly circular, but flattened above; they pass on to the forehead, and curve to join in the middle line of the skull, forming a crest. This meets at the back a crest coming from the tip of each ear-bone. The cheek-bones are huge and wide apart; the upper canine teeth are great, and their sockets mark the face. The palate is huge, wide, and not arched; and the upper middle incisors project, and are very large, cutting indeed upon three of the lower ones.
All the roughnesses for the attachment of muscles are great, and the lower jaw is immense, and the tooth next to the lower canine—the first false molar—is pointed and cutting behind. Finally, the opening for the spinal cord (the foramen magnum) is round in front, and the condyle joints are close to its anterior margin. These are changes during the growth which are worth considering, especially as they cause the animal to depart from many of its man-like characters, which are so well seen in the young and in the females.
The Orang has no uvula, and the papillæ of the back of the tongue are in the shape of the letter V. Its stomach differs somewhat in shape from that of man and the Troglodytes, but its vegetable diet determines the existence of a large intestine which has a little ending or appendix (vermiformis) as in man.