Biology / by Patrick Geddes and J. Arthur Thomson.

  • Patrick Geddes
Date:
[1925]
Catalogue details

Licence: Public Domain Mark

Credit: Biology / by Patrick Geddes and J. Arthur Thomson. Source: Wellcome Collection.

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    and the foal grows at the expense of the grass. The fundamental condition of growth is that income should exceed expenditure; there must be a surplus of nutritive material beyond what is needed to provide energy for every¬ day work and to effect the necessary repairs. It is not too much to say that the whole economy of Nature depends on the fact that green leaves are able to use some of the orange-yellow rays of the sunlight that suf¬ fuses them, to build up complex organic com¬ pounds out of carbon dioxide from the air and water with its salts from the soil. They live so far below their income that they have an abundant surplus for their off¬ spring and stores on which the whole animal world directly or indirectly depends for sustenance. Familiarity dulls our eyes to the marvel of growth—the covering of the brown earth with verdure; the desert blossoming as the rose; the bamboo rising a foot in a day; the Big Tree increasing in bulk for two thousand years; the coral-polyps forming a breakwater a thousand miles long; the Arctic jellyfish (Cyanea arctica) becoming bigger and bigger till the disc is over seven feet in diameter and the tentacles trail in the waves for over a hundred feet. Again, many an animal egg-cell forms a body that weighs a billion times as much as its beginning; and this is far exceeded in the growing up of giants—- like a Blue Whale, eighty-five feet in length,
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