326 ON SOME FOSSIL REMAINS OF MAN 



d 

 Beaver 



Lemur 



FIG. 28. Longitudinal and vertical sections of the skulls of a Beaver 

 (Castor Canadensis), a Lemur (L. Calla), and a Baboon (Cynoceplntlns 

 JV/pfo), a b, the basicranial nxis ; b c, the occipital plane ; i T, the 

 tentorial plane ; a d, the olfactory plane ; / c, the basifacial axis ; 

 c b a, occipital angle ; T I a, tenlorial angle ; d a b, olfactory angle ; 

 e f b, cranio-facial angle ; g h, extreme length of the cavity which lodges 

 the cerebral hemispheres or ' cerebral length.' The length of the 

 basicranial axis as to this length, or, in other words, the proportion;)! 

 length of the line g h to that of a b taken as 100, in the three skulls, 

 is as follows : Beaver 70 to 100 ; Lemur 119 to 100 ; Baboon 144 

 to 100. In an adult male Gorilla the cerebral length is as 170 to the 

 basicranial axis taken as 100, in the Negro (Fig. 29) as 236 to 100. 

 In the Constantinople skull (Fig. 29) as 266 to 100. The cranial 

 difference between the highest Ape's skull and the lowest Man's is 

 therefore very strikingly brought out by these measurements. 



In the diagram of the Baboon's skull the dotted lines di di, etc., give the 

 angles of the Lemur's and Beaver's skull, as laid down upon the 

 basicraniaJ axis of the Baboon. The line a b has the same length 

 in each diagram. 



