1859.] on the Gorilla. 21 



question of precise affinity as the like more anthropoid characters of the 

 female, as compared with the male, gorilla or cliimpanzee. 



Much more important and significant were the following characters 

 of the human skull. The position and plane of the occipital foramen ; 

 the proportional size of the condyloid and petrous processes ; the mas- 

 toid processes, which relate to balancing the head upon the trunk in the 

 erect altitude ; the small premaxillaries and concomitant small size of 

 the incisor teeth, as compared with the molar teeth. This 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 

 was proposed, in the present lecture, to apply them, the speaker would 

 not weary his audience or weaken his argument by citing minor 

 characters. The question at issue is, 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. Professor Owen proceeded, 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 development 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 

 absolutely 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 pre- 

 maxillaries 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 

 SimicB. In the gorilla, the median coalesced margins of the upper half 

 of the nasal bones are produced forwards ; 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 anthropic feature upon the face 

 of the living gorilla. In some pig-faced baboons there are ridges aTid 



