390 Zoological Society : — 



Believing the foregoing to be sufficient to test the respective 

 degrees of affinity to man within the Hmited group of Quadrumana 

 to which it was proposed, in the present memoir, to apply them, the 

 author would not dilute his argument by citing minor characters. 

 The question at issue was the respective degrees of affinity as be- 

 tween the anthropoid apes and man. Cuvier deemed the Orang 

 (Pithecus) to be nearer akin to man than the Chimpanzee (Troglo- 

 dytes) 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 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 absolutely less in the Gorilla, and consequently 

 the profile of the skull is less convex at this part, or less "progna- 

 thic" than in the Chimpanzee. Notvdthstanding the degree in 

 which the skull of the Gorilla surpasses in size that of the Chimpan- 

 zee, 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 im- 

 portant character, comes nearer to Man. In the Gibbons the inci- 

 sors 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 Simice. 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 afl'ording 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 and prominences in the naso-facial part of 

 the skull, but they do not really affect the question as between the 

 Gorilla and Chimpanzee. AW naturalists know that the Semno- 

 pitheques of Borneo have long noses, but the proboscidiform append- 

 age which gives so ludicrous a mask to those monkeys is unaccom- 

 panied by any such modification of the nose-bones as gives the true 

 anthropoid character to the human skull, and to which only the Go- 

 rilla, in the ape tribe, makes any approximation. 



No Orang, Chimpanzee, or Gibbon shows any rudiment of mas- 

 toid processes ; but they are present in the Gorilla, smaller indeed 

 than in Man, but unmistakeable ; they are, as in Man, cellular, 

 pneumatic, and with a thin outer plate of bone. This fact led the 

 author, in a former memoir, to express, when, in respect to the Go- 

 rilla, only the skull had reached him, the following inference, viz. : 

 " from the nearer approach which the Gorilla makes to Man in com- 

 parison with the Chimpanzee or Orang, in regard to the mastoid 

 processes., t^at it assumed more nearly and more habitually the 



