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.

    62/112 (page 58)
    PROMETHEUS found that all the characters depend on the conditions ; that such fundamental characters as *' the number of eyes an animal has or the position of the eyes in the body may be altered. In fish, for example, two eyes, one at each side of the middle line, form as distinctly an inherited characteristic as in man,yet fish can be subject so early to changed conditions (as Stockard and others show) that the animal has a single median eye instead of two lateral ones ; and many other equally striking changes are producible by changes in the chemical environment. If the fish lived continuously in these conditions they would regularly inherit a single median eye ; the two lateral eyes would be looked upon as a rare abnormality, produced by special conditions and not inherited. In truth, all characters are [60]