602 PROFESSOR SIR WILLIAM TURNER ON 



definite relation to the intellectual endowment of the people in these localities. Many- 

 other factors than the volume of the cranial cavity have to be taken into consideration 

 in the estimation of the intellectual power either of individuals or of a collection of 

 individuals belonging to the same people or race. 



In the comparison of different races with each other there is, however, evidence that 

 those in which the mean cranial capacity is low are intellectually inferior to the races 

 whose mean capacity is on a distinctly higher scale. 



If we take as an example the aboriginal Australians who are recognised as a race 

 incapable, apparently, of intellectual improvement beyond their present condition, my 

 measurements have shown that in thirty-nine men the mean cranial capacity was 

 1280 c.c, whilst twenty-four women were only 1156 c.c. Of the men, eight had a 

 smaller capacity than 1200 c.c, and four only were above 1400 c.c. ; whilst in the 

 women ten were below 1100, and only three were 1200 c.c. and upwards. 



The differences between the capacities of the native Australians and the Scottish 

 skulls are much more than can be accounted for by variations in the stature and 

 muscularity of the two peoples, and undoubtedly express a size and quality of brain 

 associated with differences in the intelligence and the mental capabilities of the two races. 



The Face. 



All craniologists from the time of Prichard and Retzius have agreed in stating that 

 in the study of the face it is important to determine the degree of forward projection of 

 the upper jaw and to decide if the face is orthognathic or prognathic. 



Gnathic Index. — In this memoir I have adopted the method followed by Sir Wm. 

 H. Flower and compared the length from basion to nasion with that from basion to 

 the alveolar point. The basi-nasal length was taken in one hundred and forty-nine 

 skulls, and ranged in the males from 91 mm. to 110 mm., and the mean was 101 '4 mm. ; 

 whilst in the females it ranged from 86 to 105, with a mean of 95 '3 mm. The basi- 

 alveolar length ranged in sixty-seven males from 81 mm. to 108 mm., and the mean was- 

 96 mm. ; whilst in thirty-one females it ranged from 79 to 102, with a mean of 91 mm. 



The gnathic index was computed as follows : 



basi-alveolar length x 100 

 basi-nasal length 



Whilst the index gives the numerical relation between the two diameters, it does not 

 necessarily express the relative projection of the upper jaw beyond the profile outline of 

 the face, for in many skulls the nasion is depressed below the plane of the glabella and 

 of the forehead generally. 



The gnathic index was computed in ninety-seven skulls, sixty-six of which were men 

 and thirty-one women. It ranged from 85"1 to 103'2, and the mean in the men was 94'5, 

 in the women 94 '8. If we take Flower's subdivision of the group, and regard an index 

 103 as marking the lowest limit of prognathism, only one specimen came into that 



