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 his daughters inherit it, but none of his sons do so. The daughters hand it on to half their sons and half their daughters, and so on. But the fruit flies in the laboratory usually live in moist air and this inheritance appears under those con¬ ditions. If they are hatched and live under dry conditions the abnormality doesn't appear—even in those daughters which indubitably inherit it. Clearly, it is not necessary to have a character¬ istic merely because one inherits it. Or more properly, characteristics are not inherited at all ; what one inherits is certain material that under certain conditions will produce a par¬ ticular characteristic ; if those con¬ ditions are not supplied, some other . characteristic is produced. Similarly, some of the fruit flies [51]