46 HEREDITY 



the argument. Sex-cells and leaves (for instance) 

 are structures repeated in the same individual. We 

 measure the variableness of the leaves, and then 

 that, not of the sex-cells, indeed, but of sexually pro- 

 duced children — whose variableness represents that 

 of the father's sex-cells plus so much variableness as 

 may be due to the fact that each child is the product 

 not of the paternal sex-cell only, but of that and 

 another. But it is found that the correlation between 

 the children thus produced is no less than that 

 between leaves repeated on one individual plant. 

 Plainly, therefore, the occurrence of bi-parental 

 reproduction has not been a cause of variation. 



Lastly, we may note one of the very latest results 

 gained by the methods of biometry. The relative 

 variability of man and woman has long been dis- 

 cussed. Some, regarding the matter from the phy- 

 sical side, have believed that woman is more variable 

 than man. Others, considering the mental characters 

 of the two sexes, have declared that woman is more 

 conservative, that is to say, less variable, than man. 

 It is man, they say, who always originates the new 

 ways of thinking, which, in any sphere, are first 

 stigmatised as heresy. Heresy, of course, is none 

 other than variation in the realm of thought, and is 

 as necessary to progress in the realm of ideas as 

 physical variation in the realm of anatomy. 



But the biometricians have clearly shown — con- 

 fining themselves, as one might expect, to the phy- 

 sical side of the question — that no difference between 

 the variability of man and woman can be detected. 

 It might indeed have been anticipated a priori that 

 no correlation between sex and variability would be 



