454 SKULLS OF WESTERX AFRICANS. App. L 



are associated the larger cranial dimensions, as a 

 general rule. But, in all, the prevalent low social 

 status, the concomitant sameness, and contracted 

 range, of ideas — the comparatively limited variety 

 in the whole series of living phenomena, from child- 

 hood to old age, of human communities of the grade 

 of the Ashiras and Fans — govern the conformity of 

 their low cranial organisation. 



In my work on the Archetype skeleton I note, 

 among other characters of the general homology of 

 bones of the human head, the degrees of variability 

 to which the several vertebral elements were respec- 

 tively subject.* 



The centrums and neurapophyses of the cranial 

 vertebrae maintain the greatest constancy, the neural 

 spines the least, in the vertebral column of mammals, 

 as in the cranial region thereof in the vast series of 

 the varieties and races of mankind : the htemal arches 

 and their diverging appendages are the seats of in- 

 termediate degrees of variation. 



Accordingly, between the lowest forms of African 

 and Australian skulls and the highest forms of Euro- 

 pean skulls, the difference in size and shape is least 

 in the basi-occipito-sphenoids, in the ex-occipitals, 

 alisphenoids, and orbitosphenoids : it is greatest in 

 the super-occipital, parietals, frontals, and nasals. The 

 maxillary and mandible are next in degree of varia- 

 bility, especially at the terminal anterior part which 

 represents the h?emal spine, and is the seat of the 

 characters which Ethnology terms " prognathism," 



* 'On tlic Archetype and Homologies of the Vertebrate Skeleton.' 8vo. 

 1843, p. loT. 



