86 



MUTUAL RELATIONS OF THE HUMAN FAMILY. 



peculiar habits and mode of life of the different races ; and Dr. Prichard has 

 pointed out a very remarkable relation of this kind, in regard to the three 

 principal types of form presented by the skull. 



84. Among the rudest tribes of Men, hunters and savage inhabitants of fo- 

 . rests, dependent for their supply of food on the accidental produce of the soil 

 or on the chase, among whom are the most degraded of the African nations, 

 and the Australian savages, a form of head is prevalent, which is most aptly 

 distinguished by the term prognathous, indicating a prolongation or forward- 

 Fig. 7. 



Profile and basal views of the prognathous skull of a Negro. 



extension of the jaws. This character is most strongly marked in the Ne- 

 groes of the Gold Coast, whose skulls are usually so formed, as to give the 

 idea of lateral compression. The temporal muscles have a great extent, rising 

 high on the parietal bones ; the cheek-bones project forward, and not out- 

 ward ; the upper jaw is lengthened and projects forwards, giving a similar 

 projection to the alveolar ridge and to the teeth; and the lower jaw has 

 somewhat of the same oblique projection, so that the upper and lower incisor 

 teeth are set at an obtuse angle to each other, instead of being nearly in pa- 

 rallel planes, as in the European. From the shape of the upper jaw alone, 

 would result a marked diminution in the facial angle, measured according to 

 the method of Camper; but this diminution is far from being sufficient to ap- 

 proximate the Ethiopian races to the higher Apes, as some have supposed it 

 to be. For, whilst the average facial angle of the European may be stated at 

 80, and that of the Negro at 70, that of the adult Chimpanzee is only 35, 

 and that of the adult Orang only 30.* Independently of the diminution of 

 the facial angle, resulting from the projection of the upper jaw, it is quite cer- 

 tain that, in the typical prognathous skull, there is a want of elevation of the 

 forehead ; but it does not appear that there is a corresponding diminution in 

 the capacity of the cranial cavity, the retreating form of the forehead being 

 partly due to the general elongation of the skull in the antero-posterior direc- 

 tion. Nor is it true, as stated by some, that the position of the foramen mag- 

 num in the Negro is decidedly behind that, which it holds in the European, 

 in this respect approaching that of the Apes ( 51) : since, if due allowance 



* The different statements made by some writers, who have estimated the facial angle of 

 the higher Apes at from 60 to 04, are due to the measurements having been made upon 

 young skulls; the projection of the jaws, in these animals, undergoing an extraordinary in- 

 crease at the time of the second dentition. 



