Prometheus, or, biology and the advancement of man / by H.S. Jennings.

  • Herbert Spencer Jennings
Date:
[1925]
Catalogue details

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

Credit: Prometheus, or, biology and the advancement of man / by H.S. Jennings. Source: Wellcome Collection.

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    BIOLOGICAL BACKGROUND the astonishment of the observer, the axolotls developed a new set of inherited characteristics, a new and diverse personality. The external gills dis¬ appeared, the body became smaller, slender, and of a very different shape, the animals came out on the land and remained there, breathing air. They now became mature in this amblystoma condition, laid eggs, and produced off¬ spring—which again, under these con¬ ditions, developed into land animals of the same sort ; and this, too, may continue for generation after genera¬ tion. The inherited characteristics are now these land characters ; these are, in detail, inherited in the typical Mendelian manner. Here we have two extremely different sets of inherited characteristics ; which one shall appear is determined by the [55]