146 
which the upper jaw (which is of course followed by the 
lower) is thrown backwards and downwards under the fore- 
part of the brain case, or forwards and upwards in front of 
and beyond it. They differ further in the relations of the 
transverse diameter of the face, taken through the cheek 
bones, to the transverse diameter of the skull; in the more 
rounded or more gable-like form of the roof of the skull, 
and in the degree to which the hinder part of the skull is 
flattened or projects beyond the ridge, into and below 
which, the muscles of the neck are inserted. 
In some skulls the brain case may be said to be ‘ round,’ 
the extreme length not exceeding the extreme breadth by a 
greater proportion than 100 to 80, while the difference may be 
much less.* Men possessing such skulls were termed byRetzius 
‘ brachycephalic, and the skull of a Calmuck, of which a front 
and side view (reduced outline copies of which are given in 
figure 27) are depicted by Von Baer in his excellent ‘ Crania 
selecta,” affords a very admirable example of that kind of skull. 
Other skulls, such as that of a Negro copied im fig. 28 from 
Mr. Busk’s ‘ Crania typica,’ have a very different, greatly elon- 
gated form, and may be termed ‘odlong. In this skull the 
extreme length is to the extreme breadth as 100 to not more 
than 67, and the transverse diameter of the human skull may 
fall below even this proportion. People having such skulls 
were called by Retzius ‘ dolichocephalic.’ 
The most cursory glance at the side views of these two skulls 
will suffice to prove that they differ, in another respect, to a 
very striking extent. The profile of the face of the Calmuck 
is almost vertical, the facial bones being thrown downwards 
and under the fore part of the skull. The profile of the face 
of the Negro, on the other hand, is singularly inclined, the 
front part of the jaws projecting far forward beyond the level 
of the fore part of the skull. In the former case the skull is 
said to be ‘orthognathous’ or straight-jawed ; in the latter, 
; * nee normal human skull does the breadth of the brain-case exceed its 
ength. = 
