THE INHERITANCE OF MENTAL ABILITY 103 
work contains a list of 32 noteworthy fathers of 38 Fellows of the 
Royal Society. 
One of the most striking illustrations of the inheritance of 
ability is afforded by the descendants of Erasmus Darwin. On 
the originality, general ability, and productiveness of Erasmus 
Darwin it is not necessary to comment. Robert Waring Darwin, 
his son, was a distinguished physician, and, like his father, a 
F.R.S. Another son, Charles, was a man of remarkable promise, 
and although he died at the age of 20, he gained the first gold 
medal of the Asculapian Society for experimental research. 
Charles Robert Darwin, the author of the Origin of Species, and 
by common consent one of the world’s greatest men of science, 
was the son of Robert W. Darwin. He married his cousin, Emma 
Wedgewood, a granddaughter of Josiah Wedgewood, F. R. S., 
the founder of the pottery works that produced the famous 
Wedgewood ware. Charles Darwin’s four sons became men of 
note: Francis Darwin, F. R. S., a prominent English botanist; 
George Darwin, F. R. S., noted astronomer, and Professor of 
Astronomy at Cambridge; Horace Darwin, F. R. S., a prominent 
engineer; Major Leonard Darwin, author of works on political 
economy, president of the Eugenics Education Society, and 
president of the International Eugenics Congress. Finally must 
be mentioned Francis Galton, cousin of Charles Darwin, grand- 
son of Erasmus Darwin, and an excellent illustration of the 
hereditary genius, the potency of which he did so much to demon- 
strate. 
The inheritance of mental and moral traits has been studied 
by Pearson and some of his colleagues by statistical methods 
similar to those employed in the study of the inheritance of 
physical traits. An intensive investigation was carried out by 
Pearson upon from three to four thousand school children. In- 
stead of attempting to compare the mentality of parents and off- 
spring, Pearson studied the resemblance in mental and moral 
traits of offspring of the same parents. The data upon which the 
comparisons were based were obtained from the teachers whose 
judgment of the mental and moral status of their pupils may be 
