Page:Popular Science Monthly Volume 4.djvu/194

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182
THE POPULAR SCIENCE MONTHLY.

sists of a perfectly homogeneous and transparent mass of jelly, and offers the paradox of an organism without organs. Nor is this absence of organs merely apparent, or owing to the imperfection of our magnifying-glasses; it is real, and every thing about these little creatures goes to prove their perfect simplicity of structure. This gelatinous, homogeneous, contractile substance has been called sarcode, and also, but improperly, animal protoplasm.

History of the Protomyxa Aurantiaca, according to Häckel.

1. The moner in a state of repose.
2. The same sending forth its pseudopodes and embedding a foreign body in itself.
3. The same in process of reproduction, after having exuded its envelope, and split up into a number of spherical masses.
4. A young moner set free after the bursting of the envelope.
5. The same in a more advanced stage, with its pseudopodes.

In repose, the moner is nearly spherical, and gives no sign of life. But soon this little ball flattens itself out, its mass expands in various directions, and these expansions, which have received the name of false feet, or pseudopodes, keep up a continual movement of protrusion and retraction. Sometimes the moner flows all in one direction, and this is its way of moving from place to place. When, in the course of this slow progress over the calcareous slime of the sea-bottom, the moner falls in with one of those microscopic organisms called diatoms, it embeds it in its own body; the alimentary substances contained in the diatom are dissolved and assimilated, and the indigestible portions are left behind as the creature moves along. Thus, we have the curious phenomenon of a creature which feeds without mouth, without stomach, without apparatus of any kind, simply by incorporating into itself, as it moves, prey of every kind. In taking food, the animal appears to be passive, its seizing on its prey being a mere incident of its moving about.