570 TRANSMISSION 



2. To quote Pearson, the male seems to " inherit more" than 

 the female because his coefficient of heredity is higher, with 

 whichever parent the comparison is made (compare lines i, 3, 5, 

 with lines 2, 4, 6). This conclusion Pearson declares is con- 

 firmed by data in eye color, as well as in stature, coat color, and 

 head index. 1 



It is a significant fact that for the races and characters here 

 involved the correlation between brother and brother is less than 

 the correlation or similarity between sister and sister (compare 

 lines ii and 12 with lines 13 and 14), which means also that 

 sisters resemble each other more closely than do brothers. 



3. The resemblance between members of the same sex is 

 closer than that between members of opposite sexes (compare 

 lines ii and 13 with line 15 ; also 12 and 14 with 16). Pearson 

 also declares that the same principle holds for eye color and 

 head index, and he is inclined to believe it general. 2 



This author points out that this principle, if general, means 

 that " inheritance in a line through one sex is prepotent over 

 inheritance in the same degree with a change of sex " ; that is, 

 that inheritance tends to run in sex lines, which means, to 

 quote Pearson (italics and parentheses mine), " that a man in eye 

 color (for example) more clearly resembles his paternal than his 

 maternal grandfather (or other male ancestors) ; a woman more 

 closely resembles her maternal grandmother than her paternal 

 grandmother. Again, a nephew is more like his paternal uncle 

 than his paternal aunt ; a niece, like her maternal aunt than her 

 maternal uncle." 3 



Future investigations will add to our knowledge in these 

 matters, and perhaps modify some general statements now con- 

 sidered safe, but the matter as stated above represents the best 

 conclusions of those who have given most careful attention to 

 the subject up to the present time. 



Comparative variability of the sexes. There has been a 

 general tendency to assert that males are more variable than 

 females. 4 This assertion has not been based on actual studies 



1 Pearson, Grammar of Science, p. 459. 2 Ibid. p. 459. 8 Ibid. p. 460. 



4 See Geddes and Thomson, Evolution of Sex, pp. 12-13; Darwin, Animals 



and Plants under Domestication, I, 457 ; Pearson, Chances of Death, pp. 256-260. 



