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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    PROMETHEUS of these structures, depending on its relation to the other cells. There comes a time after the wave of differentiation has gone over them, when they can no longer be altered ; their fate has been accomplished. This occurs at difíerent developmental periods in difíerent organisms, and in difíerent parts of the same organism, giving rise to confusing and paradoxical situations ; what is true for one organism or part is at the same period not true for another. But until the wave of difíerentiation has passed, development is adjustment to the conditions. What part of the body a cell shall produce is not determined alone by its genes, by what it contains, but equally by the conditions surround¬ ing it. In later stages we know something of the nature of the cell products which [44]