360 THE POPULAR SCIENCE MONTHLY, 



Ribot, the French authority on heredity, alleges two causes as 

 among the chief at work in cases where the law of transmission does 

 not obviously manifest itself. The first is the disproportion of an ini- 

 tiator}^ force to the amount of energy it may liberate or direct, as in 

 the slight agencies by which fires are lit or explosions set off. The 

 accidental surroundings of a mother before the birth of her child may 

 affect it for life in a way altogether disproportioned to the forces at 

 work. The military excitements in which Madame Bonaparte lived 

 just prior to Napoleon's birth are well known. Anxiety, grief, elation, 

 an unusual degree of physical health or debility at such times are pro- 

 ductive of very striking effects, quite capable of masking the likeness 

 between parent and child in form and disposition. The Greeks believed 

 so strongly in the potency of prenatal conditions that they not only 

 guarded mothers who were bearing with the kindest care, bvit used 

 even to surround them with beautiful works of art, that imagination 

 might act a favorable part. 



The second cause which Ribot thinks often tends to obscure the 

 evidence of heredity is the transformation in development of charac- 

 teristics which are the same at root. Thus a consumptive father has a 

 son who suffers from rheumatism or paralysis. Here the transmission 

 has simply been that of a feeble constitution, which gives way in the 

 first circumstances of severe trial — those favoring rheumatism, paraly- 

 sis, or other disease. The crystal of life, to use Galton's figure, is dis- 

 turbed, and reposes on a new facet. In cases where talent appears con- 

 spicuously in a family, it may be that energy and patience, productive 

 of but ox'dinary results in a father, are directed by his son to supply- 

 ing some new public want, or filling 'a position created by some sudden 

 national emergency. The constructive powers of Stephenson were less 

 remarkable than his dogged perseverance ; and when the world needed 

 steam locomotion he was the man to give it, and surmount the immense 

 difficulties in the way. His strong will is not a rare trait of character, 

 but, joined to his ingenuity, it won him success in his great opportunit3\ 

 Had Charles I. been a good king, Cromwell would probably have died 

 a brewer. Unbending will was also his chief characteristic, but at 

 Huntingdon it could have enjoyed but narrow play. 



Readers of the Monthly may remember Galton's paper on " Twins," 

 published in January, 1876. In that paper, based on wide and carefully- 

 made comparisons, it was proved that in the production of character 

 original constitution is a much more important factor than either edu- 

 cation or surroundings. The resemblance of twins when it occurs, as it 

 frequently does very strongly, continues through life in a large propor- 

 tion of cases. The same author has confirmed his opinion that Nature 

 is more powerful than nurture in moulding men, by collecting elaborate 

 testimony from all the illustrious Englishmen of science now living, 

 who say for the most part that their tastes were either innate or mani- 

 fested thems,elves very early under the influence of training, and in 



