PITHECANTHROPUS ERECTUS. 451 



the same ratio as the cranial capacity, the animal would have a body 

 almost twice as large as that of a large gorilla. But the bodily size 

 increases in a greater ratio than that of the brain and the cranial 

 capacity, so that it may be assumed that the size of an anthropoid 

 ape having a cranial capacity of 900 c. cm. would be at least three times 

 as large as that of a large gorilla; that is to say, about as large as a 

 pretty large horse. It is not easy to imagine an ape like that leading 

 the tree life of the nimble Hylobates. 



The cerebral portion of the skull of such a gigantic ape would, in 

 relation to the rest of the body, be much smaller than that of the 

 gorilla. This relatively small cranial capsule would have all the provi- 

 sions for the attachment of a powerful masticatory apparatus for fur- 

 nishing nourishment to the gigantic body, such as is shown by the 

 skull of a gorilla, but in a much greater degree than in this living 

 gigantic ape. For a jaw of such mighty proportions, which would be 

 much larger in mass than the whole of the rest of the skull, there would 

 have to be a zygomatic arch much more extensive and more strongly 

 vaulted than that which the gorilla possesses. Upon the skullcap 

 there would have been formed strong bony ridges for the attachment 

 of the temporal muscles, and these ridges would certainly have formed 

 crests in the middle and behind. The orbital rims would have been 

 raised in a much more striking manner than is seen in the gorillas' 

 skull, and the impression of the bestiality of such a gigantic ape would 

 have been much greater. 



We see, however, nothing of this in this fossil skull. It is as smooth, 

 even, and destitute of crest as the skull of an ordinary gibbon. 



The skullcap, therefore, in spite of its ape-like appearance, can not 

 have belonged to an ape, because in its excessive capacity it is dissim- 

 ilar to both a gibbon's skull and that of a great gorilla. 



There are, however, some features that separate this skull from that 

 of the apes of the Old World and ally it to that of men. These con- 

 cern the occiput. As already remarked above, there is a peculiar for- 

 mation occasioned by the abrupt separation of the planum nuchale from 

 the upper part of the squama occipitalis, determined by the torus occip- 

 italis transversus, which is certainly a pithecoid feature; compare the 

 inclination of the planum nuchale to a plane formed symmetrically 

 through the most prominent part of the glabella and of the external 

 occipital protuberance, and it will be seen that in this respect there is 

 a great difference between this skull and those of all the apes of the 

 Old World. The most diverse species of the latter show a slighter 

 variation with each other regarding the angle between the nuchal 

 plane and the glabello-protuberautial plane than is shown between 

 them and the fossil skull. Among the anthropoids I find not more than 

 three degrees of variation; in Semnopithecus maurus the inclination of 

 the nuchal surface is 4° less, and in Macacus cynomolgus it is 10° less 

 than the minimum among the anthropoids. In the Java skullcap, 



