182 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXXII. 



There are individual cases in which the fossiv are of equal length 

 or where the left fossa is the longer, but the}' are small in number in 

 adult skulls and may almost l)e regarded as exceptions. . They occurred 

 as follows: 



Length of (tuterior fossa on the two sides in human adults. 



Right ante- 

 rior fossa 

 longer (per 

 cent of 

 cases) . 



Anterior 

 fossae of equal 

 length (per 

 centof cases). 



Left iuiterif)r 



fossa IiJiif^'er 



(per cent of 



cases). 



Adults, whites, males, dolichoceplials.. . 



Adults, whites, males, niesurriilials 



Adults, whites, nuiles, brMchxcciilials . .. 

 Adults, whites, females, d(ilieliiic(_>|ilials 

 Adults, whites, females, mcsoceplials . .. 

 Adults, whites, females, hrachyccphals 

 jVdults, Indi,-ius, males, dulichdcephals . 

 Adults, ludiaus, uialcs, hrachycephals . . 

 Adults, negroes, males, ddlirhdeephals . 

 Adults, negroes, females, doliehoeephals 



Totals (93 skulls) 



63.5 



16.0 



The right anterior fossa, it is seen, exceeds ii> length the left in 

 63.5 per cent, or very nearly two-thirds, of adult human skulls, the 

 left exceeding the right in only 16.0 per cent, or approximately one- 

 sixth, of instances. 



In the crania of small children and human fetuses, and in those of 

 anthropoid apes and other mammals, the conditions differ from those 

 in human adults, namely: 



Length of anterior fossa on the tu'o sides in human fetuses, etc. 



Skulls. 



Left anterior 

 fossa longer 

 (per cent of 



10 fetuses and children, whites, brachycephals 



10 fetuses and children, colored, brachycephals 



20 fetuses and children, colored, dolicho and meso cephals 



Total (40 skulls) 



2 chimpanzees 



1 gorilla 



6 orangs 



4 gibbons 



Total (13 skulls) 



4 monkeys 



1 lemur, 1 bear, 1 deer 



«The deer. 



In human fetuses and children the percentage of cases where the 

 right anterior fossa is longer than the left is decidedly smaller than in 

 human adults, and the same is true of the cases of excess of the left 

 fossa, while the proportion of instances where the two cavities are of 

 the same length is much larger. This shows that although the 

 inequalit}' of the foss* develops in some cases earl}^ in utero, it does 



