28 HEREDITY AND CHRISTIAN PROBLEMS 



her that his father was white, and that, for many- 

 generations, there had been a white child in some 

 branch of the family.^ These, of course, are 

 instances of atavism, which, in the silk-worm, 

 appears even after more than a hundred genera- 

 tions. 



Heredity influences the internal organism, the 

 heart, the osseous, muscular, and nervous sys- 

 tems, and the siz»^ and form of the cerebral con- 

 volutions. Some families for generations are 

 distinguished by fecundity ; such were the Mont- 

 morencies, the Condes, and Guises. Longevity 

 runs in families. In some the line of threescore 

 and ten is almost always reached, while others 

 seldom have aged members. The Turgot family 

 is mentioned as one in which the fifty-ninth year 

 was rarely passed. 



Diseases run in families. One is peculiarly 

 liable to consumption, another to insanity, another 

 to rheumatism. Life insurance companies base 

 their calculations on this fact. A consumptive 

 parent is believed to entail on his offspring a 

 tendency to consumption. A friend of mine was 

 refused life insurance in one of our largest com- 

 panies because his mother died of consumption, 

 although he himself was a strong man, and his 



^ See Heredity, Ribot, p. 169. 



