NO. 1521. 



MEASUREMENTS OF CRANIAL FOSSM—HRDLICKA. 



189 



MIDDLE FOSS^. 



The absolute average length of the middle fossie in human adults 

 shows as follows: 



Middle fosscc: Average length in adults. 



"Differences from the right fossa. 



The cavities, it is seen, are slightl}' longer than the anterior ones (in 

 the proportion of 108 to 100 — a detailed comparison in a future para- 

 graph). There is again a predominance in the length of the right fossa, 

 but it is not as great or equall}' frequent as in the case of the anterior 

 fossa?. 



Length of middle fossa on the two sides in human adults. 



With the anterior fossse the conditions were: Right longer, 63.5; equal, 20.5; and left longer, 16 per 

 cent. 



In the skulls of the fetuses and 3'oung, and in those of anthropoid 

 apes and other mammals, the results differ from those in human adults. 

 There were among: 



Length of middle fossa on the two sides in human fetuses, etc. 



Skulls. 



The right 

 middle 



fossa 

 longer. 



Middle 

 fossae 

 equal. 



The left 

 middle 



fossa 

 longer. 



40 human fetuses and young . 



13 anthropoid apes 



7 other mammals 



Per cent. 

 35 

 69 

 29 



Per cent. 

 50 

 23 

 43 



Per cent. 



