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Updated: May 29, 2025
Life and growth are an attuning, death and decay are an untuning; both involve a succession of greater or smaller attunings and untunings; organic life is "the diapason closing full in man"; it is the fulness of a tone that varies in pitch, quality, and in the harmonics to which it gives rise; it ranges through every degree of complexity from the endless combinations of life-and-death within life-and-death which we find in the mammalia, to the comparative simplicity of the amoeba.
"Until I was too old to hunt, you too weak to sew the robes or cook the food." "What would happen then?" "We would die," said I. "The world would end, would have to begin all over again and wait twice ten million years until man again was evolved from the amoeba, the reptile, the ape. When we died, this dog here would be the only hope of the world."
At the lower end of the animal scale are organisms which consist of one cell and nothing more. Amoeba, to which we must refer again and again, is an example of this group which possesses an overwhelming importance to the comparative student because the origins of all the characteristics of animals higher in the scale are to be found within it.
From the amoeba, which thrusts out its pseudopodia at random to seize the organic matter scattered in a drop of water, up to the higher animals which have sense-organs with which to recognize their prey, locomotor organs to go and seize it, and a nervous system to coördinate their movements with their sensations, animal life is characterized, in its general direction, by mobility in space.
We may now turn to consider the remarkable Protamoeba, or unnucleated Amoeba. I have, in the first volume, pointed out the great importance of the ordinary Amoeba in connection with several weighty questions of general biology.
We have tables properly arranged in regard to light, microscopes, and dissecting instruments, and we work through the structure of a certain number of animals and plants. As, for example, among the plants, we take a yeast plant, a Protococcus, a common mould, a Chara, a fern, and some flowering plant; among animals we examine such things as an Amoeba, a Vorticella, and a fresh-water polype.
In like manner, in spite of the complicated apparatus which supplies oxygen and removes carbon dioxide, the respiratory system, respiration is finally the work of the cell, as in amoeba; a muscle-cell respires exactly as does the one-celled animal.
In all its structure it tells us of something earlier and far simpler, but what this earlier ancestor was we do not know. Rather more highly organized relatives of the amoeba, the flagellata, have produced a membrane, and swim by means of vibratile, whiplash-like flagella.
"The cell," I replied, relieved at the introduction of a topic that I could talk about, "and the cell wall. Protoplasmic movements, you know, and unicellular plants and animals. I'd been making sketches that day of the common amoeba of standing water." "I am not familiar with the ah with the amoeba; but doubtless its habits are interesting. And when do the school days end?
Evadne is a water flea they'll make something out of Mrs. Sarah Grand next; and Autolycus, my Autolycus! is a polymorphic worm, whatever subtlety of insult "polymorphic worm" may convey. However, I wander from the microscope. These shortbread things are fussing about hither and thither across the field, and now and then an amoeba comes crawling into view.
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