Page:Popular Science Monthly Volume 10.djvu/654

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636
THE POPULAR SCIENCE MONTHLY.

cipal inorganic constituents to be present in both in about the same proportions. There was a marked difference, however, between the two in the development of the starch-granules. In the potatoes grown under soot there was 22.5 per cent. of starch, but in the others only 17.5 per cent.—a difference of 5 per cent. Then, as for the size of the starch-granules in the good potatoes, the average was 0.175 millimetre; but in the diseased tubers it was only 0.155 millimetre. Thus it is seen that not only were the granules smaller, but their number was less. The inference is, that increase of temperature gives a great impetus to the growth of starch-granules both in size and number.

 

Asymmetry of the Eyes in Flounders.—The American Naturalist for December contains a singularly interesting paper by Prof. Alexander Agassiz on flounders, in which the author recounts his observations upon the manner in which the eyes, in that family of fishes, become placed on one side of the body. In five species of flounders he found that the eye on the blind side travels from its original place (symmetrical with the eye of the opposite side) frontward and upward on the blind side, resorbing the tissues in its way, and new tissues forming behind. This movement of translation is followed by a certain amount of torsion of the whole frontal part of the head, which, however, commences only after the eye of the blind side has nearly reached the upper edge of that side, quite a distance in advance of its original position. So far, Agassiz's observations concur, in the main, with the received theory. Further research, however, showed that the process of translation of the eye is not the same in all species of flounders. Having captured specimens about one inch in length, symmetrical and perfectly transparent, of the species Bascania, the author noticed after a few days that "one eye, the right, moved its place somewhat toward the upper part of the body, so that when the young fish was laid on its side the upper half of the right eye could be plainly seen, through the perfectly transparent body, to project above the left eye The right eye (as is the case with the eyes of all flounders), being capable of very extensive vertical movements through an arc of 180°, could thus readily turn to look through the body, above the left eye, and see what was passing on the left side, the right eye being, of course, useless on its own side as long as the fish lay on its side. This slight upward tendency of the right eye was continued in connection with a motion of translation toward the anterior part of the head till the eye, when seen through the body from the left side, was entirely clear of the left eye, and was thus placed somewhat in advance and above it, but still entirely in the rear of the base of the dorsal fin, extending to the end of the snout.

"What was my astonishment on the following day," continues Prof. Agassiz, "on turning over the young flounder on its left side, to find that the right eye had actually sunk into the tissues of the head, penetrating into the space between the base of the dorsal fin and the frontal bone to such an extent that the tissues adjoining the orbit had slowly closed over a part of the eye, leaving only a small elliptical opening smaller than the pupil, through which the right eye could look when the fish was swimming vertically! On the following day the eye had pushed its way still farther through, so that a small opening now appeared opposite it on the left side, through which the right eye could now see directly, the original opening on the right side being almost entirely closed. Soon after, this new opening on the left increased gradually in size, the right eye pushing its way more and more to the surface, and finally looking outward on the left side with as much freedom as the eye originally on the left, the opening of the right side having permanently closed."

 

Destruction of Birds in the United States.—In the course of an article in the Penn Monthly on the decrease of birds in the United States, Mr. J. A. Allen says of the heron that, though nearly useless as food, it has been enormously diminished in numbers, mostly through natural causes, but in part by the wanton act of man. "Many," he writes, "have of late been destroyed for their feathers in Florida especially; the havoc made with these poor defenseless birds is a subject of painful contemplation