NO. 1521. 



MEASUREMENTS OF CRANIAL FOSSJE—HRDLICKA. 



203 



and middle cavities. It is seen that the former exceed the latter in 

 the proportion of 143-163 to 100 in the human crania, as 119-146 to 

 100 among- the anthropoid apes, as 100-128 to 100 among the monkeys, 

 and only as 77 to 100 in the lemur. The highest proportion among 

 the human series (163 to 100) is found in the Indian male dolicho- 

 cephals, the smallest (146 to 10<>) among the white male brachycephals 

 and (150 to 100) in the young. Among anthropoid apes the highest 

 proportion (146 to 100) exists in the gorilla, the smallest (119 to 100) 

 in the gibbons; while among the monkeys similar extremes are repre- 

 sented by the baboon (128 to 10<») and by the mycetes and alouata (lOO 

 to 100). It is striking how much zoological sequence there is in the 

 distribution of these particular i-esults of comparison. The position 

 of the Indians, however, seems anomalous. 



The indexes show many characteristics of the fossse which have 

 already been ])rought out in the comparisons of the length of the 

 cavities with the lengths of the skull. To avoid repetitions and a 

 possible confusion, these features are relegated to the general sum- 

 mary. 



THE POSTERO-INFERIOR OR CEREBELLAR FOSS/E. 



The absolute average length of the cerebellar fossa? in the various 

 series of human adults is as follows: 



Posterior fossie, cereJiellar portion: Average length in adults. 



« Differences from the right fossae. 



The right cavity, it is seen, exceeds the left in length in a pronounced 

 manner in the white and Indian male dolichocephals, and a little less 

 so in two of the female series, but is decidedly smaller in the male 

 negro. In the brachycephals the differences are throughout imma- 

 terial. It is plain that correlation between the cerebellar and pos- 

 terior cerebral cavities, if it exists at all, is very limited. During the 

 measuring in whites it was very often noticed that the groove and 

 ridges of the lateral sinus on the left side were lower than those on 



