PROCEEDINGS OF THE CANADIAN INSTITUTE. II9 



The Anatomy of the Orang-Outang. By A. Primrose, M.B., Edin. 



(Read December 18, 1897.) 



A good specimen of the animal was obtained in the Anatomical Department 

 of the University of Toronto during the autumn of 1897. This animal, which is 

 the chief representaUve of the Anthropoid Apes in Asia, is found in the islands 

 of Borneo and Sumatra. A series of photographs were made of the creature, and 

 by this means the external characteristics were readily studied. The shape of the 

 cranium is very similar to the human type, but the facial region of the skull pro- 

 jects very prominently, so as to produce a markedly diminished facial angle. 

 Thus the photograph taken in profile shows a projecting muzzle, which is far 

 removed from anything of the kind found in the skull of man. The nose is short 

 and depressed, so that the anterior nares look upwards and forwards. The fore- 

 head is high and fairly prominent, in this respect differing from the condition 

 found in the Chimpanzee, in which the forehead is retreating; in the Orang, in fact, 

 there are frontal eminences to some extent developed. The eyelids are wrinkled, 

 so that a series of grooves parallel to the free margin exist in both the upper and 

 the lower eyelid. The eyes are never widely open in the Orang. From the margin of 

 the lid project well developed eyelashes. The lips are very wide^ and possess a 

 great degree of mobility: the degree of mobility may be appreciated even in the 

 dead animal when one separates the lips and exposes the jaw arches. The dental 

 formula is similar to that of man — in this specimen a noticeable feature was the 

 width cind flatness of the central incisors. There is no prominence in the region 

 of the chin. There is a very gradual curve extending from the free margin of the 

 lower lip and merging below into the outline of the neck. The ear of the Orang and 

 the Chimpanzee is said to be curiously like man; this statement is borne out in the 

 present instance. The env stands out fairly prominently from the side of the head, 

 but not more so than in many men. Along the edge of the infolded margin of 

 the ear, near its upper part, there exists in man a blunt-pointed process, to which 

 Darwin has called attention, and which is supposed to represent that part of the 

 ear which exists in many monkeys as an upper pointed extremity without any 

 infolding. We find that a well marked process representing Darwin's point is 

 .present in this Orang. There is no lobule; it is entirely absent. In man the 

 lobule is very frequently absent also. The Orang possesses a short, thick neck, of 

 great strength. Lastly, in connection with the head of this animal one must note 

 the absence of any wrinkles in the forehead. In man the wrinkling of the fore- 

 head forms one of the most characteristic forms of expression, but we find no 

 trace of such in this Orang. The fact that this form of expression is not possessed 

 by the Orang has been noticed by various observers. 



The long arms of the Orang, reaching below the knees, and the comparatively 

 short lower extremities, are noticeable features of the animal. In this respect it 

 differs from man, in whom the lower extremities exceed the upper extremities in 

 length and are much more strongly developed, thus serving more efficiently as a 

 l)asis of support in the erect attitude. It must be remarked, however^ that this 

 remarkable elongation of the upper extremities in apes is also reproduced in many 

 negroes, and occasionally in Europeans. 



In an address delivered at the recent meeting of the Anthropological Section 

 of the British Association, in Toronto, Sir William Turner selected as his subject 

 " Some Distinctive Characters of Human Structure." Among other things he 



