w Journal of Comparative Neurology. 



the sexes is greater than any difference that can be recognized between 

 the healthy and diseased brain. 



This question of the relation of brain to mental development re- 

 ceives new interest from the recently published accounts of the brain 

 of Professor v. Helmholtz, whose death occurred from the results of a 

 paralytic stroke due to hemorrhage into the right hemisphere. A full 

 account of the anatomical examination is given by Dr. David Hanse- 

 man in the Zeits.f. Psych. Phys. Sinnesorgane, XX, i, from which the 

 following data are taken. 



With a hight of 169.5 c"^- ^^ cranial measurements were, circum- 

 ference, 55 cm., length, 18.3, width, 15.5, index, 85.25, figures indica- 

 ting a hyperbrachycephalic skull. Weight of brain, 1700 gr. including 

 contained blood, but it is estimated that without the extravasated blood 

 the weight would be about 1440 gr. The right hemisphere, with the 

 exception of the frontal, parietal and occipital lobes, was nearly wholly 

 destroyed and the hemorrhage had found its way into the ventricle. 

 The vessels at the brain base were sclerosed, though unequally so. 

 Although the skull showed marked evidence of senile atrophy, the 

 brain was free from such signs. As already said, from the evidence at 

 hand it appears that very little reliance can be placed upon the size 

 and weight of a brain as an index to the perfection of the functioning 

 of the organ, and far greater significance attaches to the configuration 

 of the convolutions. In the brain of Helmholtz the gyri were highly 

 developed. The frontal lobe especially had a very complicated pat- 

 tern. The lower part of the parietal convolution is strongly devel- 

 oped, especially that part between the gyrus supramarginalis and the 

 third occipital convolution. The precuneus is also unusually pro- 

 nounced and complex. 



The author attempts to show that the parts chiefly developed are 

 such as correspond to the association spheres as defined by Flechsig. 

 It is, of course, hard to begin the examination of the brain of a noted 

 man with entire objectivity and it must be admitted that similar condi- 

 tions of the brain surface may be found in the case of those who have 

 never emerged from the level of sheltering obscurity. It must also be 

 remembered that a mind like that of Helmholtz might, if directed in 

 other fines of activity, scarcely have attained to a greater recognition 

 than that of many another man regarded as simply clever. 



Another point touched upon in the article referred to is the effect 

 of early and transitory hydrocephalus in preparing the way for unusual 

 brain development. Intracranial pressure due to results of such dis- 

 ease, the author thinks, may be an adequate occasion for heightened 



