CHAP. XX.] 



OF THE HUMAN BRAIN. 



365 



900 grammes. Broca places it somewhat higher, fixing 

 upon 32 oz., or 907 grammes, as the limit for the female, 

 and 87 oz., or 1,049 grammes, as the lower limit of 

 weight for the male brain, compatible with ordinary 

 Human Intelligence. 



The brain-weight of Idiots may, however, and frequently 

 does, fall far below the limits above assigned, and that 

 either from atrophic disease ensuing some time after birth 

 or from congenital defect. Subjoined is a table given by 

 Thurnam of the lowest fifteen brain- weights as yet re- 

 corded among Idiots:* 



BRAIN-WEIGHTS OF SMALL-HEADED IDIOTS. 



(&) Some of the Conditions coinciding with high Brain- 

 weights: Very low brain- weights are, as we have seen, 

 only consistent with Dementia or Idiocy. Very high 

 brain-weights may, however, be met with, either (1) in 

 association with these same morbid conditions or among 

 insane persons belonging to other categories ; (2) in very 

 ordinary sane individuals ; or (3) among the most highly 

 intellectual members of society. That the latter asso- 



* Loc. cit., p. 29. References to the original descriptions of 

 these brains are cited. 



