Anatomy. — ''On the topographical relations of the Orbits in 

 infantile and adnlt skulls in man and apes '. By Pwï.h. Boi.K. 



(Communicated in the meeting of March 23, I'd 8). 



In the Proceedings of tliis Academy of 1909 two papers l\y tlie 

 present nut hor were published, dealing with the position, shifting 

 and the inclination of the Foramen magnnm in the Primates. In 

 these papers it was shown that the topographical relations of this 

 Foramen in the infantile skulls of the Primates and more parti- 

 cularly with the Antliropomorphons apes present only small deviations 

 from those in the human sknll. It is only in their suhsecjuent growth 

 that a difference between the development in man and the Primates 

 becomes apparent. This difference comes in the main to this tliat 

 in man the original topograhical relations, such as are found in 

 the infantile skull, are permanent, the sknll retaining infantile 

 characteristics; in the i-emaining Primates, on the other haud, and 

 especially in the Anthropoid apes, these juvenile conditions are 

 replaced by others. The chief phenomenon, which may be 

 briefly stated afresh here, is that in ijifantile sknlls of man and 

 anthropoid apes the foramen magnum lies in the middle of the 

 cranial base, and during growth is shifted backwards over a longer 

 or shorter distance in the direction of the occipital pole of the 

 cranium, while in man it remaijis situated in the anterior half of 

 the cranial base. It is difficult to reconcile this result of my investi- 

 gations with the conception, often met with in literature, that the 

 more occipital position, as found in these aj)es, would be the 

 original one, so that it would be in man that a forward shifting 

 would take place. Now of such a forward displacement, presumed 

 on theoretical grounds, nothing appears during individual development 

 in man. On the contrary. From about the eighth year, i.e. in 

 conjunction with the commencement of the loss of the milk-teeth, 

 also in man a slight backward shifting is stated, which is not of 

 much significance, however. So the characteristic difFeience between 

 the human and anthropoid skulls is that in the foi'mer infantile, 

 not to say foetal, characteristics are retained. While the infantile 

 skulls of man and anthropoid apes thus show a great similarity in 

 this respect, the adult skulls grow dissimilar, and it is not the 



