NO. 1521. 



MEASUREMENTS OF CRANIAL FOSS.E—HRDLICKA. 



185 



the spacious than in the sinall crania. The comparison of the two 

 diameters, the mean ventral length being- taken as 100, was as follows: 



Relation between the greater dorsal and mean ventral length of tlie ukull. 



Skulls. 



No. of 

 spec- 

 imens. 



White males 



White females 



Indian males 



Negroe.s, both sexes 



In the largest 

 skulls. 



No. of 

 spec- 

 imens. 



108. 5 : 100 

 109. 9 : 100 

 109.2:100 

 110. 6 : 100 



In the small- 

 est skulls. 



108. 5 : 100 

 108. 5 : 100 

 108. 2 : 100 

 108. 8 : 100 



These differences make it necessary to contrast the length of the 

 fossse in skulls of extreme sizes with the ventral rather than dorsal 

 length of the skull, by doing which the following- proportions are 

 obtained (the mean ventral maximum antero-posterior diameter ])eing- 

 taken as 100): 



Mean length of I lie anterior fossa' compared with mean, ventral length of skull in the largest 



and. smallest adidt crania. 



The differences are somewhat smaller than when the fossae were 

 compared with the external cranial length, in all except the w^hite 

 males; but in all of the groups, with the exception of the Indian males, 

 the average of the relative proportions of the frontal cavities in the 

 smallest skulls remains perceptibly above that in the largest speci- 

 mens. The conclusion before reached of a predominance of relatively 

 longer anterior fosss in the smallest than in the largest crania is 

 hereby confirmed. 



The same interesting fact can also be brought out by contrasting 

 the size of the skull with a number of the largest and smallest relative 

 values of the anterior cavities. This procedure'" gives the following 

 results in the different groups of adult crania: 



9 skulls of white males with the highest relative length ^j of the anterior fossa:*. . 16. 5 



9 skulls of white males with the lowest relative length of the anterior foss;e ... 16. 9 



6 skulls of white females with the highest relative length of the anterior fossae. 15. 4 



6 skulls of white females with the lowest relative length of the anterior fossae. . 15. 8 



4 skulls of Indian males with the highest relative length of the anterior fossae. . 15. 5 



4 skulls of Indian males with the lowest relative length of the anterior fossae. . . 15. 9 



5 skulls of negroes with the highest relative length of the anterior fossae 15. 8 



5 skulls of negroes with the lowest relative length of the anterior fossae 16. 1 



« Represented by the mean of the greatest external length and breadth of the skulls. 

 b That is, the highest relation of the mean length of the two fossae to the maxi- 

 mum antero-posterior (glabello-occipital) diameter of the skull. 



