NO. 1521. 



MEASUREMENTS OF CRANIAL FOSSAE— HRDLICKA. 



197 



No regular or substantial difference is apparent. There is no com- 

 pensation in this regard ])etween the postero-superior and the anterior 

 cavities, Avhich latter, it will be remembered, are relatively' shorter 

 in the largest than in the smallest crania. 



The absolute and relative length proportions of the postero-superior 

 fossa?, contrasted between adults and young, man and animals, sexes, 

 races, and in the main cranial forms, are presented in the following talile: 



Length proportions of podero-superior fossse in relation to greatest external length of the skull. 



Subjects. 



Adults: 



Whites, males — 



Dollehoeephals 



Mesoeephals 



Brachyeephals 



Whites, females — 



Dolichoceiihals 



Mesoeephals 



Braeliyeeplials 



Indians, males — 



Doliehocephals 



Brachycephals 



Negroes — 



Males, dolicho- and meso- 

 eephals 



Females, doliciio- and me.so 

 cephals 



Human fetuses and young 



Anthropoid apes: 



Chimpanzees 



Orangs 



Gibbons 



Monkeys and lemurs: 



M„n,r„.i,.l„ps 



C( liiis liijiKih iicH); 



Aldiiitiii Sf iiirukl 



Midas 



Lem ur varitis 



Num- 

 ber of 

 skulls. 



Average j ^^^mf 



external : jg^^fh of 



maximum twWnoc 



lene-th of ,tneiwopos- 



skull ' tero-supe- 



^^^^^- I rior fossae. 



19.4 

 18,7 

 18.2 



17.8 

 17.8 

 17.3 



18.3 

 16.9 



18.6 



11.9 

 11.9 

 7.5 



8.2 

 7.5 

 7.0 

 4.1 

 6.0 



mm. 

 82.1 

 80.7 

 77.3 



75.9 

 76.9 

 75.3 



80.8 

 73.8 



78.7 



75.5 



41.1 



49.8 

 51.0 

 30.8 



32.5 

 28.0 

 24.5 

 16.5 

 17.3 



Average 

 relation of 

 the length 

 of the fos- 

 sse to the 



dorsal 

 length of 

 the skull. 



42.4 

 43.0 

 42.4 



42.6 

 43.3 

 43.5 



44.2 

 43.6 



41.7 

 42.8 

 40.7 



39.6 

 37.3 

 35.0 

 40.2 

 28.7 



Average 

 relation of 

 the length 

 of the fos- 

 sse to the 

 ventral 

 length of 

 the skull. 



Num- 

 ber of 

 skulls. 



45.9 

 46.0 

 46.4 



45.8 

 46.8 

 47.4 



48.5 

 48.0 



46.9 



45.0 

 48.5 

 42.3 



42.2 

 41.8 

 41.7 

 42.0 

 32.5 



13 



The average relative proportions of the postero-superior cavities 

 differ, it is seen, but little between human adults and the young; taken 

 as a whole, the middle fossae presented a moderate, the frontal cavities 

 a marked, diversity at the two periods of life. If we compare the rela- 

 tive proportions of the postero-superior fossa? in the smallest fetuses 

 of the series, namely, in those where the vertex-breech length was less 

 than 20 cm. with those where it was above that, we find somewhat 

 different conditions, as shown in the following table: 



