Biology of the Seasons (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated.1920 Excerpt: ... OLD AGE AND DEATH LL around us, if we will, we may see living creatures _ growing from the apparent simplicity of germs to the obvious complexity of adult organisation. But from their earliest hours they are singled and sifted. Out of a million oyster-embryos energetically swimming in the sea, it may be that only one reaches maturity, and even then it may be that it has only survived to become what Huxley playfully called "a gustatory flash of summer lightning." In all ordinary cases, however, throughout the animal kingdom there is abundant survival, and those who escape the dangers of the first part of the Mirza bridge form a strong contingent. As we watch them we see that they wax stronger, attain a stable constitution, adjust themselves masterfully to their environment, and give rise to others like themselves. From almost every point of view the curve of their life rises, and they are full of promise. We see life victorious and triumphant. But as we continue to watch, we begin sooner or later to detect a rift within the lute. We begin to detect symptoms of decadence. Vigour slackens, the range of activities narrows, the thrusts of adverse circumstances or of intrusive disease are less successfully parried, the organisms drift instead of swimming in the environmental current, they lose their grip on their surroundings which seem to close in upon them, they sometimes show internal symptoms of weakening and atrophy--in a word, they qrow old. Our problem is to try to understand more clearly why it is that the curve of life, after attaining what the thoughtful biologist Treviranus called a vita maxima, should begin to droop, sinking quickly or very slowly to a nadir of vita minima, at the threshold of death. Why do living creatures grow old, or, to be m...