NO. 1521. MEASUREMENTS OF CRANIAL FOSS.E—HRDLICKA. 



209 



Summarij of the results of measaremevts uf the cranial />,s.s\'c — Continued. 



Results obtained from the absolute measurements 

 and by comparing the length of the fossse with 

 the dorsal and ventral lengths of the skull. 



Results obtained by comparing the length of the 

 fossK with their combined length, and among 

 themselves. 



MIDDLE Foss.t;— continued. 



(c) Differences are quite immaterial in whites, 



though there is a tendency to smaller 

 relative proportions in the females: in 

 negroes, smaller in the females. 



(d) Differences quite immaterial, though .some- 



what smaller than in any other adult 

 human series in the female negro. 



(e) The relative length of the middle fossse is 



throughout smaller in the dolicho- than 

 in the brachycephals. 



CEREBR.\1, P.VET OF THE POSTERIOR FOSS.E. 



1 (a) The average aljsohite length of the right 

 cavity is decidrdly shorter than that of 

 the left side in all the series of human 

 adults and anthropoid apes, moderately 

 .shorter in the human young, and slightly 

 shorter in the lower i)rimates and other 

 animals. 



(6) Individually, the largest percentage of 

 longerleft foss;e and the most pronounced 

 differences Ijetween tlic Icngtii of the two 

 cavities occur (as with the anterior and 

 middle fossse) in the human adults, and 

 then in anthropoid apes. 



(c) The length of the posterior fossa stands 

 frequently in compensatory relation with 

 the combined length of the anterior and 

 middle fossae on the .same side. 



There are no regular or large differences in the 

 relative length of the postero-superior 

 fossre between the largest and smallest 



skulls. 



3 (o) The mean relative length of the postero- 

 superior cavities, compared with the mean 

 ventral antero-posterior diameter of the 

 skull, is, in the human fetuses and young, 

 slightly greater than in some series of the 

 adults and smaller than in others. 



(b) It is smaller than in adult man in anthro- 



poid apes (except the orang), monkeys, 

 and especially in the lemur. 



(c) There is no material difference between the 



sexes. 



((/) From the racial ptiintof view, the length is 

 relatively greatest in the Indians: it is 

 nearlyalikt'in the whites and the negroes; 

 finally, 



(e) It is greater in the brachycephals than in 

 the dolichocephals among the whites, but 

 smaller in the former than in the latter 

 among the Indians. 



MIDDLE FOSS.E — continued. 

 (c) Fossse smaller in the female negro. 



(d) FossEe somewhat smaller in the negroes of 

 both sexes than in other human adults 



(e) The relative length of the middle fossse is 

 throughout smaller in the dolicho- than 

 in the brachycephals. 



CEREBR.^L P.\RT OF THE POSTERIOR FOSS.K. 



1 [a) The average absolute length of the right 

 cavity is decidedly shorter than that of 

 the left side in all the series of human 

 adults and anthroi>oid a|ies, nKKlenitely 

 shorterin the human young, and slightly 

 shorter in the lower jirimates and other 

 animals. 



(6) Individually, the largest percentage of 

 longer left fossie and the mt)st pro- 

 nounced differences between the length 

 of the two cavities occur (as with the 

 anteriorand middle fosste) in the human 

 adults, and then in anthropoid apes. 



3 (o) The left fossa in the young shows smaller, 

 the right about equal index, as compared 

 with that in adults; contrasted witli the 

 combined length of the anterior and mid- 

 dle fo.ss8e, it appears smaller than in the 

 adults. 



(6) It is smaller than in adult man in anthro- 

 poid apes (except the orang), monkeys, 

 and especially in the lemur, 



(c) There is no material dilTerence between the 



.sexes. 



(d) Prom theracial pointof view, Ihelengthis 



relatively greatest in the Indians; it is 

 nearly alike in the whitesand the negroes; 

 finally, 



(e) The index is somewhat greater in all but one 



of the series of dolichocephals than in the 

 brachycephals, and comparison of the 

 length of the postero-superior fossae with 

 that of the anterior and middle fossse, 

 shows excess for dolichocephals in all the 

 series. 



The combined length of the three cerebral fossae is greater on the left in from 64 

 to 80 per cent of the adult dolicho- and mesocephals, but there is a prevalence of 

 greater length on the right side in the brachycephals, the young and the primates, 

 Proc. N. M. vol. xxxii— 07 14 



