12 ON THE AFFINITIES OF THE BRAIN 



On the other hand, we must recollect that the proportion sub- 

 sisting* between the adult brain in man and the body has been put 

 as low as I : 50 T ; and that though this proportion is lower by as 

 much as 15 than most authorities would rate it, some such dispro- 

 portion must have prevailed in those cases in which the brain of 

 an adult Negro is recorded as reaching no greater weight than 753 

 grammes 2 , or 1 lb. 10-59 oz « 



The weight of the body of a nearly adult female chimpanzee is 

 given by Professors Sharpey and Ellis, on the authority of Pro- 

 fessor Owen, as 61 lb. The relation of weight between such a 

 body and the brain of our orang, which weighed 12 oz. } would be 

 1:81.3*. 



Let us suppose that the Negro, the weight of whose brain, as 

 given by Tiedemann, amounted to no more than 26 oz., weighed 

 altogether as much as 8 stone, or 1792 oz. The proportion between 

 his brain's weight and his body's would then have stood as 1 : 68-9, 

 as against a proportion taken between analogous weights in the 

 apes of 1 : 8- 13. It will be seen from this that the absolute weight 

 of the human brain is a more sharply differentiating characteristic 

 than is its relative weight. 



It will be convenient to give the following measurements and 

 their mutual relations in a tabular form, using, for the sake of 

 economy of space, the letters of the alphabet to denote each par- 

 ticular measurement : — 



a. The length from the root of the olfactory nerve to the anterior 

 extremity of the brain. 



b. The length from the point of the middle lobe to the posterior 

 extremity of the brain. 



c. The length of the cerebellum. 



d. The breadth of the cerebellum. 



e. Length of cerebral hemispheres. 



f. Length of the corpus callosum. 



l In Orang = 1 finch. : 2|inch. = 1 : 1-64. 



a : b. < In Man = 2§inch. : scinch. = 1 : 1.95. 



( In Chimpanzee 4 = 44 mm. : 69 mm. = 1 : 1-56. 



1 Huschke, 1. a, p. 60. 



2 Tiedemann, citt. Huschke, p. 73. 



3 * Quain's Anatomy,' by Sharpey and Ellis, vol. ii. p. 433, note, 1856. 



4 Schroeder Van der Kolk et Vrolik, citt. 'Nat. Hist.. Review,' No. 1, p. 80. 



