G58 



Taking into consideration that the certainly still more correct lines 

 of Donaldson') give to r a value of 0.2316, we may call this result 

 very satisfactory. On grounds to be discussed afterwards we may 

 admit that indeed tlie exponent of correlation luithm the same species 

 of all Vertebrates is 0,22. . . 



In my previous communication of the result for Mammals I had 

 borrowed, on behalf of a provisional comparison with Man, for the 

 calculation of k available evidences from the 2"<^ edition (of 1893) 

 of Vierordt's "Daten und Tabellen". Calculating with the general 

 exponent of correlation 0,56 I found then a somewdiat diiferent value 

 of k for Man and for Woman. If I had made use of more accurate 

 evidences, the cephalisation would have been found identical for the 

 two sexes, as has indeed been proved by Lapicqie ') in 1907, and 

 at the same time it would have been proved that between Man and 

 Woman of different size the same exponent of correlation obtains as 

 between species that are equivalent with regard to the organisation 

 of the nervous system, but differ in the size of the body. 



I can now affirm this by two more series of evidences. Placing 

 namely the four groups of English men of average size, borrowed 

 from Marshafj-, used for my calculation of the exponent of corre- 

 lation for Man, beside the four groups of average English women 

 of his Table XVIII (I.e., p. 498) we find 63685 G. and 54432 G. for 

 the average weight of the bodies and 1353.7 G. and 1233.2 G for the 

 average weight of the brain. The result of the calculation is r = 0,594. 



For the average weights of the brain of English and Scottish men 

 and women we obtain 1J^75 G. and 1235 G., according to seven different 

 observers, cited in the new edition of Vierordt's "Daten und Tabellen".^) 

 The weights of the body for full-grown men and women of that 

 nationality, according to Roberts, cited there, are 63010 G. and 52170 

 G. (deduction made for what Roiberts indicates for the weight of 

 the clothes). With this value r can be calculated at 0,568. 



Calculating with the weights of the body according to Roberts 

 and the weights of the brain according to Marshall we find 0,498. 

 The average of these three results is 0.553. 



There are no sufficient evidences at hand for testing this sexual 

 difference in species of animals. Kohlbrugge^) gives the weights of 



^) For these comparisons E and e were borrowed from the graphical repre- 

 sentation in Donaldson's publication of 1898 (1. c. p. 322). 



~) "Le poids encephalique en fonction du poids corporel entre individus d'line 

 même espèce". 1. c. p. 344. 



3) Dritte Aufl. Jena 1906, p. 23—24, 75—76. 



*) Zeitschr. f. Anatomie und Morphologic. Bd. II (1900), p. 51 — 55. 



