Page:Popular Science Monthly Volume 6.djvu/177

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THE NATURAL HISTORY OF THE OYSTER.
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seems disposed to favor such a view. However, I believe all the proof as yet is on the side of its being a process, an organ, so to speak. Now, there are a good many of these bird-heads in the community, and very useful things they are. Let an animalcule too large for prey come fooling around these little Bryozoa, and one of the bird-heads will give it a nip such as to make a second one unnecessary. But these Bryozoa are in danger of being cloyed with dirt. These bird heads, like so many ants, pick off the annoyance. Is not all this

Fig. 5.—Anatomy of a Bryozoon.—1, the skeleton cells; 2. diagram of an individual Bryozoon; a, the region of the mouth surmounted by a crown or tuft of tentacles; 3, an avicularium, or bird's-head process.

pretty? And it is quite ludicrous, too. And why should not Nature like a wee bit of drollery now and then?

If a pile of oysters be examined soon after leaving the water, especially if taken off a pretty clean bottom, a number of specks, about a quarter of an inch in width, may be seen adhering to the oyster, chiefly the upper side. They look like grease-spots, or small lamps of jelly. They are little sea-anemones, collapsed and dead. Alive in the water these are pretty objects, having a disk of a flower-form, with an orifice in the centre which opens into the animal's stomach, and which is really its mouth. (See Fig. 8). Such, then, is something of the oyster's environment. With such surroundings, so much of beauty, with a spice of Nature's humor, just enough to make this beauty true and pure, on the principle that a person is known by the company he keeps, the oyster might be set down as an individual of refined tastes.

Something should be said of the oyster's most intimate and familiar friend, a certain dapper little fellow in a scarlet jacket with trimmings of gold. From its size and form it is sometimes called the pea-crab; but, from the fact that it is only found in the oyster, it is gener-