21 



that there is no question about a displacement of the orbita, in the 

 baby as in the adult the orbita is situated snbcerebral, which 

 accounts for tlie complete absence of supraorbital ridges in man. 



The subcerebral position of the oibitae is a typical feature of the 

 human skull, by which it is distinguished from all other mammalian 

 skulls. In tliis respect the Orang skull is most like that of man. 

 Parenthetically I call attention to my former pronouncement, quite 

 in harmony with the fact established here: that all typical human 

 somatic properties are persisting fetal features. 



The Figures 4A and 4B also induce me to say something relative 

 to the so-called flattening of the skull of Anthropoids. The hypothesis 

 that the skull of Anthropoids has been flattened through mechanical 

 causes, I consider, in principle, erroneous, as it is based only on 

 deficient observation and inaccurate measurement. As to the latter 

 it must be considered as a fundamental error when, in determining 

 the lenglh-height-index of the skull, the greatest length of the skull 

 is considered to be the distance between two points lying on the 

 outside of the skull. According to this method the height of the 

 skull should be measured from the basion to the superior margin 

 of the crista sagittalis. For a comparison of the forms of skulls of 

 allied species measures should be used that cannot be influenced by 

 a difference in thickness of the cranial bones, or by other adventi- 

 tious circumstances. Points on the inside of the skulls should be used. 



But the hypothesis that the Anthropoid skull is flattened, rests on 

 deficient observation, as stated above. A flattening of the skull would 

 necessarily entail a transformation of the cranial cavity. Now when 

 comparing the relative figures it will be seen that in Macacus the 

 brains of the adult individual with his large supra-orbital ridges are 

 not flatter than those of the young individual, in which the ridges 

 were lacking; it will furthermore be seen that the cranial cavity 

 of the adult Orang in the frontal region is still as much vaulted as 

 in the young specimen. 



The anthropomorphous child has a frontal vault that is visible on 

 the outside. The absence of this vaulting in the adult skull is not 

 to be ascribed to a flattening, undergone by the frontal region, but 

 is due to a shifting of the orbits anteriorly and to their consequent 

 precerebral situation. From the vaulted front a new roof overlaps 

 the orbita, and the originally a[)ert frontal vault has thereby be- 

 come an occult one. 



