80 PRACTICAL ANATOMY. 



gested by Broca. This system of measures constitutes 

 the cephalic index of Retzius, which is generally stated 

 to be 80, or 78, or 75, which means so many per cent, of 

 the long diameter, and is of much practical importance 

 in differentiating between the skulls of different races, 

 thus: The Mongol races are brachy cephalic ; the Lapps 

 have the most brachy cephalic skulls, the cephalic index 

 in these people often rising as high as 90. Contrasted 

 to these are the cephalic indices of the negroes, Caledo- 

 nians, Australians, and others. In these people the 

 cephalic index is about 72. The highest types of the 

 white races have a skull the cephalic index of which is 

 about 78. In taking these measurements it must be re- 

 membered that they are to be taken at the extreme points 

 on the section. Another series of measurements, in 

 which the vertical diameter is compared with the trans- 

 verse, is also interesting, but less important than the in- 

 dex already discussed. In order to obtain the vertical 

 diameter, a transverse section should be made vertically 

 from the junction of the coronal and sagittal sutures, 

 slightly oblique, downward, and backward, so that the 

 lower portion of the section shall pass just in front of the 

 occipital condyles. This measurement determines the 

 relation of breadth to height, but, owing to the varia- 

 tions in the shape of the skull in the same races, it is not 

 of much importance. An illustration, however, is not 

 uninteresting; it must be understood, however, that the 

 basis of measurement is the length of the head, as before 

 described, and which is taken as 100. The index of 

 height (vertical index) in the Kaffir is 73, in the Hotten- 

 tot 71 2 I both skulls are dolichocephalic, with an index 

 of 72; this, as can be seen at a glance, may at times 

 serve to distinguish different skulls whose ordinary 

 cephalic indices may be alike. Many other measure- 



