SIZE AND WEIGHT OF BEAIN. 577 



inferior frontal convolution, the posterior extremity of the middle frontal, and 

 the gTeater part of the ascending frontal convolutions are supplied by the 

 middle cerebral. The orbital surface is supplied, outside the orbital sulcus, by 

 the middle cerebral : within that sulcus (including the olfactory bulb) by the 

 anterior cerebral. 



Parietal lohc. — AU the convolutions of the parietal lobe are supplied by the 

 middle cerebral artery. 



The occijjital lolw is supplied by the posterior cerebral artery. 



Temporo-gphenoldal lolw. — The superior, and upper part of the middle temporo- 

 sphenoidal convolutions are supplied by the middle cerebral arteiy. The lovrer 

 portion of the lobe by the posterior cerebral. 



Inner surfaee. — The whole anterior and upper portion, as far back as the 

 parieto-occipital fissure, is supplied by the anterior cerebral artery ; the cuneate 

 lobule and the occipito-temporal region by the posterior cerebral. 



The grey svlidanee at the base of the cerebrum is supplied by small twigs 

 from the adjacent vessels of the circle of AVillis, or the commencing cerebral 

 vessels. 



Central jJarts — eoiptis .strlatmn. — Both nucleiis caudatus and nucleus lenticu- 

 laris are supplied almost exclusively by the middle cerebral artery. The anterior 

 part of the caudate nucleus only being supplied by the anterior cerebral. 



The 02)tic thalamus is supplied by the posterior cerebral artery, except its inner 

 and outer portion, which is supplied by the middle cerebral. 



The corpora quadrigemina and corpora geniculata are both supplied by the 

 posterior cerebral artery. 



For further details on the subject the reader is refen-ed to Vol. I., p. 378, and 

 to a series of articles by M. Duret in the Archives de Physiologic for 1873 and 

 1874. 



SIZE AND WEIGHT OP THE ETTCEPHALOIf. 



In the following table, illustrating the average weight of the adult male and 

 female brain, the results obtained by Sims. Clendinning, Tiedemann, and J. Reid 

 have been brought together in such a form as to exhibit in groups the most 

 commonly prevailing weight ; the numbers being also simplified by the omission 

 of fractions. (Sims, ** Medico-Chirurg. Trans."' vol. xix., pp. 3.53 — 7 ; Clendinning, 

 " Medico-ChiiTu-g. Ti-ans.," vol. xxi., pp. 59 — 68; Tiedemann, *' Das Hirn des 

 Negers," Heidelberg, 1837, pp. 6. 7 ; Reid, '• London and Edinburgh I^Ionthly 

 Journal of Medical Science," April, 1843, p. 298, &c.) 



According to Table A, the maximum weight of the adult male brain, in a 

 series of 278 cases, was (J.j oz., and the minimum weight 34 oz. In a series of 

 191 cases, the maximum weight of the adult female brain was .56 oz., and the 

 minimum 31 o.z. ; the difference between the extreme weights in the male subject 

 being no less than 31 oz., and in the female 2.5 oz. By grouping the cases toge- 

 ther in the manner indicated by brackets, it is shown that in a very large pro- 

 portion the weight of the male brain ranges between 40 oz. and 53 oz., and that 

 of the female brain between 41 oz. and 47 oz. The j;7Y'rrt///«^ weights of the 

 adult male and female brain may therefore be said to range between those terms ; 

 and, by taking the mean, an average weight is deduced of 49^ oz. for the male, 

 and of 44 oz. for the female brain. — results which correspond closely with the 

 statements generally received. 



Although many female brains exceed in weight particular male brains, the 

 general fact is sufiiciently shown, that the adult male encephalon is heavier than 

 that of the female, — the average difference being from 5 to G oz. This general 

 superiority in absolute weight of the male over the female brain has been ascer- 

 tained to exist at every period of life. In new-born infants the brain was found 

 by Tiedemann to weigh on an average from \\\ oz. to 1 5| oz. in the male, and from 

 10 oz. to 134- oz. in the female : — a fact of considerable interest in practical 

 midwifery, for it has been shown that difficult labours occiu- in by far the 

 largest number in the birth of male children. (Simpson,^ London and Edinbm-gh 

 Monthly Journal of Medical Science, 1845,) j 



VOL. u. p p 



