THE MAN-LIKE APES. 1 45 



separating them from the maxillary bones remaining visible 

 after the adult dentition has been obtained." {Mivart.)* The 

 Simiidce. have a bony meatus or canal to the ear. The back 

 part of the head, which among the Guenons is flat, is convex 

 among the Simiidce. The palate is long and narrow, and the 

 margins of the jaws nearly parallel. The lower jaw is always 

 in one piece, the two halves being firmly ossified in the middle. 

 The dental formula of the Man-like Apes is If, C|, Pf, M| 

 (z>., 32 teeth in all); their inner upper incisors are larger, and 

 the lower are smaller than the outer pair; the canines are large, 

 and between them and the neighbouring incisor above there 

 is a vacuity (or diastema), and, below, between them and the 

 nearest pre-molar. The upper pre-molars have three roots, and 

 the lower, two; the upper molars have four tubercles, their 

 crowns being relatively wide ; the lower molars have five 

 tubercles, but the posterior has no hind talon. 



The opening for the passage of the spinal cord is situated 

 towards the posterior portion of the base of the cranium, and 

 is thus further from the centre than in Man. 



Except among the Gibbons, the vertebral column shows in 

 the sacral region indications of that curve— or concavity in the 

 back between the two convexities of the neck and loins — which 

 is one of the distinctive characters of the human skeleton. 

 The processes for the interlocking of the vertebrae, which are 

 large in the lower Anthropoids, are much reduced in the 

 Man-like Apes, and become inconspicuous in Man. 



The breast-bone is flat, and resembles that of Man, and, in 

 all, except the Orang, is composed of two bones. The arm- 



* '^'^tc\m&-^% oi Anthropopithecus niger and Gorilla gorilla, in the Derby 

 Museum, Liverpool, in which the permanent teeth have not yet developed, 

 have the premaxillary suture quite obliterated. 



.^— V. 2 L 



