EXTERNAL FORM OF THE MAN-LIKE APES. 737 



almost attained the length of those of lions and tigers. On the upper 

 part of the skull, which is rounded in youth, great bony crests are 

 developed on the crown of the head and on the occiput, and these are 

 supported by the high, spinous processes of the cervical vertebrae, and 

 thus supply the starting-point for the powerful muscles of the neck 

 and jaw. The supraorbital arches are covered with wrinkled skin, 

 and the already savage and indeed revolting appearance of the old 

 gorilla is thereby increased. A comjiarison of the two illustrations 

 (Figs. 1 and 3) which accompany the text will make this clear. 



These distinctions are not so striking in the female as in the male 

 gorilla. Although there is much which is bestial in the appearance of 

 an aged female, yet the crests, so strongly marked in the male, the 

 projecting orbits, and strong muscular pads are absent in the female, 

 as well as the prognathous form of the skull and the length and thick- 

 ness of the canine teeth. The aged female gorilla is not, in her whole 

 structure, so far removed from the condition of the same sex in youth 

 as is the aged male. The structure of the female has on the whole 

 more in common with the human form. It has been said, and indeed 

 on good authority, that the female type should take the foremost place 

 in the study of the animal structure, since it is the more universal. 

 But H. von Nathusius maintains that we must take both sexes into 

 consideration in the study of domestic animals, since both are needed 

 to determine the breed.* I accept this condition in the scientific study 

 and description of wild animals also, of every kind and species. All 

 that is said of the universal type of the female animal is and must 

 remain in my eyes a mere phrase. Only the accurate observation of 

 males and females, and of young individuals of both sexes, can throw 

 sufficient light on the history of the race. The male animal is the 

 larger, and predominant with respect to the complete development of 

 certain peculiarities of form in the specific organism, since these are 

 doubtfully present in the adult female, and are either altogether absent 

 in the immature young, or only rudimentary. 



Let us now consider, in the first place, the prototype of the species, 

 the aged male gorilla in the full strength of his bodily development 

 (Fig. 1). This animal, when standing upright, is more than six feet 

 in height, or two thousand millimetres. The head is three hundred 

 millimetres in length. The occiput appears to be broader below than 

 above, since the upper part slopes like a gabled roof toward the high, 

 longitudinal crest of the vertex. The projecting supraorbital arches 

 start prominently from the upper and central contour of the skull. In 

 this species, as in other apes, and indeed among mammals generally, 

 and especially in the case of the carnivora, ruminants, and multi-ungu- 

 lates, eyebrows are present. In the gorilla these consist of a rather 

 scanty growth of coal-black bristles, about forty millimetres in length. 

 Beneath the projecting supraorbital arches are the eyes, opening with 



* " Vortriige iiber Viehzucht und Rassenkenntniss," vol. i, p. 61. Berlin, 1872. 

 VOL. xxviu. — 47 



