C59 



tlie body of the Javanese Biideng- (Semiu)[)itlieciis maiinis and 

 pyn-lius) relating to IJ female and 7 male individuals and the 

 weights of the brain of 4 female and 3 male individuals. It is 

 a great pity that a few errors mnst have slipped into these precious 

 statements of the weights of the bodies ^). It is, however, possible to 

 calculate 0.553 or 0.586 for the intersexual exponent of correlation, 

 either when correcting the presumable errors or when omitting 

 these erronical weights of the body. 



What has been stated for Man, considered in connection witli the 

 rational meaning of the exponent of correlation 0.55 still to be dis- 

 cussed, gives ns already a right to admit that for Vertebrates in 

 general the following law exists : The sexe.i dijjerliig in size of one 

 species are in the quantity of brain proportional to each other as two 

 different species loith identical organisation of the nervous system. 



The attention may here be called to the fact that this law is in 

 accordance with the result of the latest investigations about the 

 hereditary transmission of sex '^), as with those of Dumbar on the 

 sero-biological behaviour of the sexes in plants and animals. 



Further I want to point out that there is a connection between 

 the relation of the two sexes found and the non-existence of the 

 disproportion in the relative length and thickness of the bones, 

 which is so striking a feature between the large and the small 

 individuals of one species. ^) Both sexes behave, in this respect too, 

 as nearly related species of very different sizes. 



*) The uniformity of the correlation found between quantity of 

 brain and size of body in all classes of Vertebrates, however 

 striking, cannot, [troperly, surprise ns, as we did eliminate a priori 

 all other important intluences on the quantity of the brain, save 

 the size of the body. That uniformity affords proof that indeed we 

 succeeded in eliminating those other influences and, moreover, that the 

 size of the body influences the quantity of the brain in the same 

 way in all classes. 



One may, however, consider it strange that the well known in- 

 crease of the relative amount of white substance (composed chiefly 

 of medullated fibres) contrary to the grey substance (containing the 



1) It seems indeed that in three cases pounds are written erroneously for kilos. 



~) G. GoRRENS and A. Goldsmidt, Die Vererbung und Bestimmung des Geschlechtes. 

 Berlin 191R. 



'^) Species with a relatively slight difference of size (as e.g. Hylobales syndactylus 

 and H. leuciscus) show a disproportion in a reverted sense: between species of 

 very different size this is scarcely perceptible. 



^) The passage between brackets is added in the English translation. 



