CONSANGUINITY 188 



perfection. Even where no positive evil exists on 

 either side, heredity by metamorphosis, as we have 

 seen, may produce a distinctly neuropathic condition, 

 the preliminary to insanity, and other troubles, and this 

 is a matter which would naturally escape the notice 

 of the statisticians. Moreover, we must bear in mind 

 that such terms as cousin cover many different degrees 

 of actual relationship. X has a son, we will say, 

 resembling his mother. The brother of X has a 

 daughter also resembling her mother. The young 

 people are first cousins, but they are physically and 

 morally as unlike each other as strangers. On the 

 other hand, X may have a daughter taking after him- 

 self, and his brother a son who likewise takes after 

 his father ; these cousins will be as closely allied as 

 brother and sister. It is manifestly unsafe, therefore, 

 to conclude that this or that class of marriage is in- 

 nocuous from bare statistical returns, conveying no 

 information as to particular cases. 



The statistics of insanity in connection with con- 

 sanguineous marriages in different localities vary 

 enormously. Huth, remarking upon such discrepan- 

 cies, considers the higher figures to be worthless as 

 evidence, on the ground that they are obviously 

 compiled by biassed persons. But they are just what 



