Heredity, health and personal beauty.

  • Shoemaker, John V. (John Veitch), 1852-1910.
Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: Heredity, health and personal beauty. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    Darwin, and more and more as lie advanced in life, but that their affirmation pervades his whole theory of evolution by natural selection as a minor but great and indispensable cause of the change observable in organisms. We must here preliminarily clear the ground of obstacles to a correct understanding of the particular point which we have in view for discussion,—the heritability of acquired characters,— by describing the distinction made between the elfects in the transmission of life in organisms, due to the pressure of external circumstances under purely natural conditions, as compared witli similar effects taking place in them through the agency of man, or exceptionally arising we know not whence. The first conception is derived from that view of life which regards it as tending to perpetuate, while modifying, the characters of or- ganisms through countless ages, presenting itself to our minds as indissolubly linked heredity. The second conception is de- rived (according to its advocates) from that view of life which ascribes to characters, derived from changed habits and the use and disuse of vital parts, through artificial selection (man's agency mingling with nature's), obedience to the same law of heredity. It is the second class of these conditions, assumed as inducing change, which some persons deny as having the slightest influence toward hereditary transmission. These latter condi- tions are, nevertheless, those which are denominated by all persons acquired characters, although, as will appear later, that is only for convenience of distinction, characters represent- ing the change produced by purely natural selection having been acquired, and universally admitted in various degrees to have been acquired, by all who believe in any form of organic evolution,—that is, of course, congenitally acquired. This objection is made in the face of many contradictory fact^, contained in the inclusive contradictory fact of all, that every organism must be, at any given instant of time, the