ANATOailCAL STRUCTURE OF ANTHROPOID APES. 61 



addition to this division, which is of great value in 

 the rapid and superficial, yet sound classification of 

 racial skulls, Retzius has constituted another. He 

 has characterized skulls of which the profile is 

 straight, or nearly straight, as ortliognathous {recht- 

 zdlmige) ; and those of which the maxillary region is 

 very prominent, as j;ro(7?ia^/iOMS {schiefzdhnige). These 

 orthognathous and prognathous skulls may be either 

 dolichocephalic or brachycephalic* 



In applying this classification by Retzius to an- 

 thropoids, the gorillas and chimpanzees have been 

 characterized as dolichocephalic and prognathous, 

 the orang-utans and the gibbons as brachycephalic 

 and prognathous. Several scientific men have 

 sought to establish the noteworthy distinction that 

 dolichocephalic anthropoids are found in Africa, 

 and brachycephalic anthropoids in Asia. This dis- 

 tinctive characteristic is held to agree with the 

 geographical and ethnological conditions of the 

 continents in question.f Virchovv remarks in a later 

 work that the skull of a gorilla becomes longer with 

 every year of life, but that this is not so much due 

 to the cranium as such, as to its bony outworks, such 

 as the strongly developed supra-orbital arches, the 

 enlargement of the frontal sinuses, etc. Measure- 

 ments rather tend to show that the young gorilla 



* Ethnologische Schriften, nach dem Tode des Verfassers gesam- 

 melt von dessen Sohne Professor Gustav Retzius, p. 33 : Stockholm, 

 1864. 



t Zur Kenntniss des OrangsTcopfes, etc., p. 3. Virchow observes 

 (Verhandlungen der Berliner Anthropologischen Gesellschaft, Marcli 

 18, 1876) : " The fact that the gibbon, as well as the oiang-uLan, 

 is brachycephalous is of great geographical interest." 

 4 



