VARIATIONS IN BRAIN- WEIGHT. 125 



grammes. Among the microcephalies, in which the 

 brain may be considered as having attained approxi- 

 mately its full weight i.e., those more than seven years 

 old we have the case of Helene Becker cited by 

 Bischoff. This girl died at seven years of age with a 

 stature of 78 cm., and a brain-weight of 219 grammes. 



If from the fifty cases cited by Marchand children 

 less than ten years of age are excluded, there remain 

 twelve cases in which the brain-weight was less than 

 500 grammes, fourteen in which it ranged between 500 

 and 800 grammes, and in eleven cases between 800-1,015 

 grammes. In these instances the brain is not only of 

 the small size indicated by the enclosing skull, but at 

 the same time the skull is apt to be unusually thick, 

 and either the brain does not fill it so completely as 

 normally, or the enlargement of the cerebral ventricles 

 by fluid causes the actual weight of the nerve substance 

 to be smaller ; so that when the volume of the brain is 

 deduced from its weight on the assumption that it was 

 normal in its proportions, it is in some instances found 

 to be much smaller than the cranial cavity. Further- 

 more, even this mass often contains a large proportion 

 of undeveloped or degenerate tissue, and the encephalon 

 may thus be of even less functional value than its small 

 size would suggest. It thus appears that the essential 

 anatomical feature in microcephalism is not so much the 

 small size of the brain as its deficient construction, of 

 which this small size can usually be taken as an index. 

 On the other hand, that small size and great faultiness in 

 construction are not necessarily connected is suggested 

 by Marchand, who has pointed out that the micro- 

 cephalies are by no means necessarily aphasic, and that 

 one Antonia Grandoni, a woman living to be forty-one 

 years of age, with a stature of 132 cm., and a brain- 

 weight of 289 grammes, both sang and spoke readily, 



