PITHECANTHROPUS ERECTUS, ETC. 361 



from 45 to 55 m.m.; and in modern European crania the 

 former measures from 65 to 85 m.m., the latter from 25 to 

 45 m.m. It is evident that, on the whole, the nuchal sur- 

 face is greater in the ancient than in the modern type of 

 skull ; the nuchal muscles, also, must have been developed 

 to a correspondingly greater extent ; on the other hand, the 

 supra-nuchal part is greater in modern skulls, because the 

 brain is bi^crer an d the nuchal muscles less in fossil man. 

 Both the ancient and modern forms are entirely human, 

 and resemble the occipital configuration found in baby apes. 

 In baby anthropoids, as in men, the head is poised upon 

 the body, and the muscles merely fixed for purposes of 

 gentle nodding and turning the head. In men it is so 

 through life, but in the adult anthropoids the head has to 

 become, as it were, an integral part of the trunk in order 

 that the individual may exert its great strength through its 

 huge jaws. The occipital ridge ascends towards the vertex 

 like the temporal, and thus extends the nuchal surface, until 

 a crescentic plateau, continuous with the mastoids, offers a 

 firm attachment for the nuchal muscles. 



Dubois throws much stress upon the fact that the 

 occipital ridge (linea nuchas superior) and linea nuchse 

 inferior emerge together from the external occipital pro- 

 tuberance (the mesial part of the occipital ridge). These 

 two lines enclose the insertion of the complexus. The 

 complexus has a similar insertion in the gibbon, but I have 

 been unable to find such an insertion in man. 1 It is 

 probably an individual peculiarity. The pit, also, which 

 occurs in the nuchal surface of the Bengawan skull, and 

 marks probably the insertion of the recites posticus miner, 

 is not confined to gibbons, as Dubois has stated, but occurs 

 in many human skulls. 



In most of the many lists that give us the differential 

 diagnosis of man, it is stated that he only has a mastoid 

 process. Herein the anthropoids have been wronged ; for 

 although the simian mastoid may not have the human form, 



1 Martin {Globus, bd. lxvii., No. 14, 1895) states that he has observed 

 a similar arrangement of the nuchal lines in human skulls. 



