To the Editor of the Popular Science Monthly.
Reading an item, attributed to a writer in Science Gossip, on the "Food of the Water-Tortoise," in the "Popular Miscellany" of your July number, showing that that reptile appears "to have a special relish for the food of the cat," it occurred to me that I might also relate a fact which came under my own observation bearing upon this subject: During last summer I found an ordinary snapping-turtle (Chelydra serpentina) in a field adjoining my residence, and near a brook which empties into Boone River, a few rods below. It was a vicious old fellow, and more than ordinarily curious to me from the fact that it had more than a hundred leeches clinging to its shell and various portions of its skin. I had some suspicions that my captive had committed depredations upon my young black Cayuga ducks; but disliking to murder it "in cold blood," I let it go, and it speedily disappeared in a deep hole in the brook. Some days afterward, while passing near the place, I heard a duck squawling and splashing in the water, and went at once to learn the cause. I found that this same turtle had seized one of my ducks by the foot, and was trying to drag her under the water—for "carnivorous purposes!" The duck was full-grown, and would have weighed five or six pounds, but would soon have been killed if I had not rescued it. I got hold of the bird and drew her to the shore, but the turtle held on, till I was able to secure him. Of course, he caught no more of my ducks.
But this reminds me of another interesting fact. These black Cayuga ducks—said to have descended from ancestors captured at Cayuga Lake, New York, by reason of long domestication and high feeding—have come to have very heavy bodies and short, small wings. Owing to the disuse of the latter, they have become so far atrophied that "well-bred" birds are quite incapable of flight. In the summer of 1875, one of my half-grown ducklings had the misfortune to lose one of its legs. After some days' absence it hobbled home from the river on one foot, the other having no doubt been torn off by one of these same predacious turtles. The little bird speedily recovered from the injury, though it never attained the full size of its mates. It hopped about quite briskly on its single foot, using its wings to surmount obstacles or increase its speed. The consequence was that its wings grew to such size and length that it was capable of flying twenty or thirty rods, and possibly much farther. It could rise easily out of the water, and once on the wing was able to clear the bank and a high fence—in all, a quite abrupt rise of fifteen or twenty feet—and thus speedily reach home, while its mates were slowly waddling through the grass. My flock of ducks showed in a striking manner the result produced by the long disuse of their wings; while the unfortunate one-legged bird as strikingly evidenced how rapidly "compulsion to more diligent use" produced a very decided and important modification of the wings, increasing their strength, as well as the length of the feathers.Charles Aldrich.
Webster City, Iowa, July 6, 1877.
SPECTROSCOPIC DISCOVERY OF OXYGEN IN THE SUN.
CELESTIAL chemistry has taken another stride forward. In a paper recently read before the American Philosophical Society, and printed in the American Journal of Science and Arts, Dr. Henry Draper announces the discovery of oxygen gas in the sun, the fact being arrived at and verified by a long course of spectroscopic observations.
Viewed in any of its numerous aspects, this discovery is of immense interest. Whether as an extension of our knowledge of solar physics, solar chemistry, and the nature of the spectrum itself, or as throwing further light upon the constitution of the universe; whether as bearing upon cosmical theories that have attracted much attention, or as a triumph over the difficulties of complicated experiment, or, finally, as an illustration of hereditary genius in science, where a line of research opened brilliantly by the father nearly half a century ago, has been pursued with equal brilliancy to this crowning result—however regarded, this exploit of the younger Draper must command unqualified admiration.
As has been repeatedly shown in our
