Page:Popular Science Monthly Volume 43.djvu/882

862 others, as the Charleston Mountains, push their lofty summits into so cold an atmosphere that they obtain a covering of the boreal pines and firs. These higher mountains, when rising from the lower Sonoran deserts, present in succession all the extratropical zones of North America, which, from their close juxtaposition, may be here studied to unusual advantage. In ascending or descending such slopes the change from one zone to another is quickly recognized, and the altitude of first appearance of the various new species encountered may be recorded with considerable confidence. Not so, however with the species lost, for, except in the case of trees and such strikingly conspicuous forms as the yuccas, some of the cactuses, the creosote bush (Larrea), and a few others, it is exceedingly difficult to detect the disappearance of species when passing out of their ranges.

The Rattlesnake's Rattle.—The idea that the rattles of a rattlesnake correspond with its years is, according to Dr. Arthur Stradling, incorrect. "When the little Crotalus is born," this author says, "its tail is furnished with a single tip of horn, incapable of producing any sound by the violent vibration which its owner nevertheless communicates to it when excited. In some near relations of the rattlesnake, such as the çurucucuçurucucú [sic] of Brazil, this horny claw or nail persists throughout life without addition thereto. But in the rattlesnakes proper—and there are many species of them—two, and sometimes three, joints appear during the first few months of the creature's life; then and later there is probably no definite relation between their number or frequency of development and its age, though they may be proportionate in some measure to its rate of growth. Broods of young serpents belonging to this genus which I have reared have exhibited great diversity in this matter; so much so, that it has been impossible to base any calculation on observations of the phenomena presented by them. The overlapping 'thimbles' or cones of which the rattle is composed are thin, dry, and exceedingly brittle, and in consequence the instrument is easily broken off when it has reached the length of from one to two inches, though longer specimens are occasionally seen; twenty joints make an exceptionally big rattle. This shedding of the rattle is in all cases accidental, and is due to external causes, not a constitutional and periodical function like the casting of the skin. When it breaks off at the root or in the middle, there is generally no trace left of a fracture having taken place, as the thimbles are all alike, and any one forms a symmetrical termination to the organ. Whatever purpose the rattle may serve in the snake's economy—and its use is still involved in some obscurity—it undoubtedly does not represent the owner's age, nor the sum total of his manslaughter."

Energy in Organic Evolution.—In two papers, Mr. John A. Ryder has endeavored to demonstrate the potency of energy as a factor in organic evolution, and to show that the form of the hen's egg is determined by mechanical means while the egg membranes and shell are in process of formation within the oviduct. The development of the figure of eggs is regarded by him as a purely dynamical problem, or one in which energy is applied in a definite manner to a mass in statical equilibrium within the oviduct. The moment motion is set up to propel the egg through the duct the forces operative in determining the figure of the as yet unformed shell depend upon the physiological activity and condition of tone of the muscular walls of the oviduct.

Cremation of Cholera-dead.—From a paper read by Dr. Robert Newman before the Northwestern Medical and Surgical Society of New York in favor of the cremation of persons dying of cholera, it appears that there are now fifteen crematories in this country, and that two thousand and seventeen incinerations took place between 1887 and 1892, of which eight hundred and sixty-eight were at New York. The Earl Memorial Crematory, at Troy, is the most costly. Thirty-two active cremation societies are scattered over the country. Nearly all those who participated in the discussion of the paper agreed with the author as to the importance of cremation in cholera. In respect to the objection—the only really important and valid one that has been made—that cremation facilitates the concealment of