Heredity and the Law of Evolution. 303 



leave descendants unworthy of them ; in fact, advantage has been 

 taken of this fact in order to call in question hereditary transmis- 

 sion, whereas we should rather perhaps find in it a striking con- 

 firmation of the law. Galton, in his work on English judges, 1 

 observes that of thirty-one judges raised to the peerage previous to 

 the close of the reign of George IV., nineteen are still represented 

 in the peerage by their descendants, and twelve peerages are 

 extinct. Having minutely investigated the cause of this extinction, 

 he discovered them in social reasons, in motives of convenience 

 which led to ill-assorted unions : those peers whose families soon 

 disappeared ' married heiresses.' Even when unequal matches do 

 not produce such grave results as these, it is not to be doubted 

 that, in virtue of the laws of heredity, they must cause a degenera- 

 tion, which, being again and again repeated, must of necessity 

 bring about the extinction of a gifted family, or, what is worse, its 

 mediocrity. It is evident that a son may take after his indifferently 

 gifted mother as readily as after his illustrious father, and that, as 

 in any case he must be the resultant of the two, the chance of his 

 being inferior to his father is as two to one. 



Considered as an indirect cause of decline, heredity acts by way 

 of accumulation. Every family, every people, every race brings 

 into the world at their birth a certain amount of vitality, and of 

 physical and moral aptitudes, which in course of time will become 

 manifest. This evolution -has for its causes the continual action 

 and reaction between the being and its surroundings. It goes on 

 until the family, people, or race has fulfilled its destiny, brilliant 

 for some, distinguished for others, obscure for the majority. When 

 this sum of vitality and of aptitudes begins to fail, decay commences. 

 This process of decay may at first be of no moment, but heredity 

 transmits it to the next generation, from that to the following one, 

 and so on till the period of utter extinction, if no external cause 

 interferes to stay Ihe decay. Here, then, heredity is only an 

 indirect cause of degeneration, the direct cause being the action . 

 of the environment, by which term we understand all action from 

 without not only climate and mode of life, but also manners, 



1 Pages 130-133. See the concluding chapter of the work, with regard to 

 the question whether great men leave no posterity. 

 14 



