LAWS OF GALTON AND MENDEL 177 



The effects of heredity may be studied with the aid 

 of statistics, general rules being deduced from the 

 examination of a very large number of cases. Fran- 

 cis Galton was the first to apply this method to biolog- 

 ical questions, with special reference to phenomena of 

 variation. In his famous books on heredity, "Heredi- 

 tary Genius," 1869, and "Natural Inheritance," 1889, 

 he established the foundations of a new science, Bio- 

 metrika. He was followed by many scientists, among 

 them his immediate successor, K. Pearson, bj r Weldon, 

 Bateson, Darbishire and others, whose observations 

 have been recorded in a special magazine, Biometrika. 



The first great generalisation Galton deduced 

 from his vast statistical studies (he collected data rel- 

 ative to one hundred and fifty families, tabulating 

 the most varied characters, physical or mental) is the 

 following: when the variations of one character or 

 one faculty are considered, there seems to be one 

 constant average for every generation and every 

 divergence from the average is compensated by an- 

 other divergence. For instance, whether the father is 

 above or below the average, the son will have a tend- 

 ency to vary from the average in the opposite direc- 

 tion. It has been frequently observed that the sons 

 of great men were rather poorly gifted and that the 

 parents of remarkable men were inferior to the aver- 

 age. "The more bountifully the parent is gifted by 

 Xature, the more rare will be his good fortune if he 



