258 PROFESSOR OWEN ON THE EXTERNAL CHARACTERS 
head upon the trunk in the erect attitude; the small premaxillaries and concomitant 
small size of the incisor teeth as compared with the molar teeth. The latter character 
relates to the superiority of the psychical over the physical powers in Man: it governs 
the feature in which Man recedes from the brute; as does also the prominence of the 
nasal bones in most, and in all the typical, races of Man. The somewhat angular form 
of the bony orbits, tending to a square, with the corners rounded off, is a good Human 
character of the skull, which is difficult to comprehend as an adaptive one, and therefore 
the better in the present inquiry. The same may be said of the production of the floor 
of the tympanic or auditory tube into the plate called ‘‘ vaginal.” 
Believing the foregoing to be sufficient to test the respective degrees of affinity to 
Man within the limited group of Quadrumana to which it is proposed, in the present 
Memoir, to apply them, the argument need not be diluted by citing minor characters. 
The question at issue is the respective degrees of affinity as between the anthropoid 
Apes and Man. Cuvier deemed the Orang (Pithecus) to be nearer akin to Man than 
the Chimpanzee (Troglodytes) is. That belief has long ceased to be entertained. I 
proceed, therefore, to compare the Gorilla, Chimpanzee, and Gibbon, in reference to 
their Human affinities. 
Most naturalists entering upon this question would first look to the premaxillary 
bones, or, owing to the early confluence of those bones with the maxillaries in the 
Gorilla and Chimpanzee, to the part of the upper jaw containing the incisive teeth, on 
the size and direction of which depends the prognathic or brutish character of a skull. 
Now the extent of the premaxillaries below the nostril is not only relatively but abso- 
lutely less in the Gorilla, and consequently the profile of the skull is less convex at this 
part, or less ‘‘ prognathic,” than in the Chimpanzee. Notwithstanding the degree in 
which the skull of the Gorilla surpasses in size that of the Chimpanzee, especially when 
the two are compared on a front view, the breadth of the premaxillaries and of the four 
incisive teeth is the same in both. In the relative degree, therefore, in which these 
bones are smaller than in the Chimpanzee, the Gorilla, in this most important character, 
comes nearer to Man. In the Gibbons the incisors are relatively smaller than in the 
Gorilla, but the premaxillaries bear the same proportional size in the adult male Siamang. 
Next, as regards the nasal bones. In the Chimpanzee, as in the Orangs and Gibbons, 
they are as flat to the face as in any of the lower Simie. In the Gorilla the median 
coalesced margins of the upper half of the nasal bones are produced forward, in a slight 
degree it is true, but affording a most significant evidence of nearer resemblance to Man. 
In the same degree they impress that anthropoid feature upon the face of the living 
Gorilla. In some pig-faced Baboons there are ridges and prominences in the naso-facial 
part of the skull, but they do not really affect the question as between the Gorilla and 
Chimpanzee. All naturalists know that the Semnopitheques of Borneo have long noses ; 
but the proboscidiform appendage which gives so ludicrous a mask to those Monkeys is 
unaccompanied by any such modification of the nose-bones as gives the true anthropoid 
