Hereditary genius : an inquiry into its laws and consequences / by Francis Galton.

  • Galton, Francis, 1822-1911.
Date:
1869
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Hereditary genius : an inquiry into its laws and consequences / by Francis Galton. Source: Wellcome Collection.

    19/424 (page XV)
    то THE EDITION OF 1892 xr appealing to experimental evidence, it is now certain that the tendency of acquired habits to be hereditarily trans¬ mitted is at the most extremely small. There may be some few cases, like those of Brown-Séquard's guinea- pigs, in which injury to the nervous substance of the parents affects their offspring ; but as a general rule, with scarcely any exception that cannot be ascribed to other influences, such as bad nutrition or transmitted microbes, the injuries or habits of the parents are found to have no effect on the natural form or faculties of the child. Whether very small hereditary influences of the supposed kind, accumulating in the same direction for many genera¬ tions, may not ultimately affect the qualities of the species, seems to be the only point now seriously in question. Many illustrations have been offered, by those few per¬ sons of high authority who still maintain that acquired habits, such as the use or disuse of particular organs in the parents, admit of being hereditarily transmitted in a suflicient degree to notably affect the whole breed after many generations. Among the^ illustrations much stress has been laid on the diminishing size of the human jaw, in highly civilized peoples. It is urged that their food is better cooked and more toothsome than that of their ancestors, consequently the masticating apparatus of the race has dwindled through disuse. The truth of the evidence on which this argument rests is questionable, because it is not at all certain that non-European races who have more powerful jaws than ourselves use them more than we do. A Chinaman lives, and has lived for centuries, on rice and spoon-meat, or such over-boiled diet as his chopsticks can deal with. Equatorial Africans live to a great extent on bananas, or else on cassava, which, being usually of the poisonous kind, must be well boiled