FOSSIL RLMAINS OF MAN. 171 



a term which has been rendered, with more force than 

 elegance, by the Saxon equivalent, ' snouty.' 



Various methods have been devised in order to express 

 with some accuracy the degree of prognathism or ortho- 

 gnathism of any given skull ; most of these methods being 

 essentially modifications of that devised by Peter Camper, 

 in order to attain what he called the ' facial angle.' 



But a little consideration will show that any * facial 

 angle ' that has been devised, can be competent to express 

 the structural modifications involved in prognathism and 

 orthognathism, only in a rough and general sort of way. 

 For the lines, the intersection of which forms the facial 

 angle, are drawn through points of the skull, the position 

 of each of which is modified by a number of circum- 

 stances, so that the angle obtained is a complex resultant 

 of all these circumstances, and is not the expression of any 

 one definite organic relation of the parts of the skull. 



I have arrived at the conviction that no comparison 

 of crania is worth very much, that is not founded upon 

 the establishment of a relatively fixed base line, to which 

 the measurements, in all cases, must be referred. Nor do 

 I think it is a very difficult matter to decide what that 

 base line should be. The parts of the skull, like those of 

 the rest of the animal framework, are developed in suc- 

 cession : the base of the skull is formed before its sides 

 and roof ; it is converted into cartilage earlier and more 

 completely than the sides and roof: and the cartilaginous 

 base ossifies, and becomes soldered into one piece long 

 before the roof. I conceive then that the base of the skull 

 may be demonstrated developmentally to be its relatively 

 fixed part, the roof and sides being relatively moveable. 



The same truth is exemplified by the study of the 

 modifications which the skull undergoes in ascending from 

 the lower animals up to man. 



