200 BRAIN-WEIGHT AND SIZE IN RELATION 



Dr. Broca, on the male French skull, yield a mean capacity of 1502 

 cubic centimetres, or 91 cubic in., representing an average brain- 

 weight of 50 "G oz. Morton, taking his average from five English 

 skulls, gives the. great internal capacity of 96 cubic in.; while Dr. J, 

 B. Davis arrives at a capacity of only 90 '9 cubic in., from the 

 examination of thirty-two skulls, male and female ; and for the 

 Scottish and Irish, each of 91-2 cubic in., from an examination of 

 thirty-five skulls. But unfortunately the Davis collection, so rich in 

 other respects, derived its chief English specimens from a phreno- 

 logical collection ;, and, along with a few large skulls, contains "many 

 small and poor English examples."* The average weight of the 

 English brain may therefore, as Dr. Davis admits, be assumed to be 

 higher than the mean determined by him. " Still a comparison with 

 actually tested weights of brains shows that there cannot be any 

 material error." The average brain- weight of twenty-one English- 

 men, as given by him, is 50-28 oz., that of thirteen women is 43-13"; 

 and of the combined series, 47*50. The results determined by the 

 same process in relation to the other nationalities of Europe are 

 exhibited in detail in Dr. Davis's tables, printed in the "PhUosophieal 

 Transactions." 



Such averages are, at best, only approximations to true results ; 

 and when obtained, as in Morton's English race, from a very few 

 examples, or in Dr. Davis's, from exceptional skulls, collected under 

 peculiar circumstances or for a special purpose, they must be tested 

 by other observations. According to Dr. Morton, for example, the 

 mean internal capacity of the English head is 9Q cubic in., while that 

 af the Anglo-American- is only 90 cubic in. Such a conclusion, if 

 established as the result of comparison of a sufl6.ciently large number 

 of well authenticated skulls, would be of great importance in its 

 bearing on the influence of change of climate, diet, habits, &c., as 

 elements affecting varieties of the human race. But determined as 

 it was in the Morton, collection, from five English and seven Anglo- 

 American specimens, it can be regarded as no more than a mere 

 chance result. Banged nearly in the order of mean internal capacity 

 of skull, the following are the results arrived at, mainly by gauging 

 the skulls in various collections available for such comparisons of 

 difierent races of mankind. In presenting them here, I avail myself 

 of Dr. Thurnam's researches, augmenting them with other data sub- 



*" Thesaurus Craniorum;" App., p. 347. 



