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 If we compare two pieces from the same lot, one at a temperature of 20 degrees, one at 35 degrees, the difference in hardness is a matter of the conditions. But if at the same temperature we com¬ pare a sample of paraffin that melts at 25 degrees with one that melts at 40 degrees, the difference in hardness is a matter of constitution. If now we inquire as to the origin of the difference in constitution, tracing the two samples perhaps to oils from different regions, we embark upon an investigation strictly comparable to research in heredity. Such analysis must be apphed to all cases. Though stature is always dependent both upon hereditary con¬ stitution and upon environment, the difference in stature between Jones and Smith may be purely a matter of heredity, the difference between the [69]