Marriage and disease : a study of heredity and the more important family degenerations / S.A.K. Strahan.

Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Marriage and disease : a study of heredity and the more important family degenerations / S.A.K. Strahan. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    HEREDITY. Heredity is that mysterious influence which fore- ordains that the offspring shall be in the likeness of its parents. It is one of Nature’s great fundamental laws, and it is universal. In the meanest forms of animal and vegetable life, as in the highest, each family must produce its like. Grapes are not gathered from thorns, nor figs from thistles. All through Nature, from the amoeba to man, from the yeast-plant to the oak, every kind produces after his kind. Yet plants and animals are not tied down by this law to endless sameness. Certainly Nature will not permit any rude violation of this law of hereditary transmission, hut, where the change is sufficiently gradual, where it is, so to speak, the work of Nature herself, it is with the aid of this very law that modifications are built up, the changes brought about in the individual by the action of the environment being repeated and perpetuated in the offspring by the action of the laws of heredity. These modifications sometimes tend toward the elevation of the family type—evolution, and sometimes toward its extinction—dissolution. IO