Page:Popular Science Monthly Volume 21.djvu/727

Rh lumber sawed in Australian mills is not made from trees of only ten to fifteen years of age, and it is probable that very few of the eucalypts planted in California are as old as fifteen years from the seed. Our native trees of so recent growth are not used for or made into lumber, and nothing but soft and sappy wood can be expected from trees so young." Facts bearing upon the profit of eucalyptus-growing for fuel purposes are furnished by the yield of twenty acres of a plantation belonging to General Stratton, of which, after charging every item of cost, and a yearly rental of five dollars per acre, the net profits were $3,866.04 in eleven years. Notwithstanding that too much may have been claimed by enthusiastic friends in relation to the sanitary and medical value of certain species of the eucalyptus, "there is enough, minus exaggeration, to justify their being regarded as of unquestionable merit."

How Flies climb.—Herr H. Dewitz has communicated to the Berlin Society of Natural History some facts that bear very strongly against the generally received theory that flies adhere to perpendicular walls and ceilings by virtue of some sucking power in their feet. He asserts that the feet of flies can not possess the sucking property ascribed to them, for they are hard and destitute of muscles. The theory has long been contradicted by the experiments of Blackwall, who found that flies could climb the sides of a jar under the receiver of an air pump, where there was no atmospheric pressure; and who asserted that the power of adherence was due to a sticky matter secreted from the foot-hairs of flies. This assertion was generally regarded as not proved, and the case has rested there. Dewitz reports that his investigations have shown that Blackwall was right. He has watched the exudation of the sticky matter from the feet of the flies by fastening one of the insects to the under side of a plate of glass and viewing it under the microscope. A perfectly clear liquid was seen to flow from the ends of the foot-hairs and attach the foot to the glass. When the foot was lifted up, to be put down in another place, the drops of the sticky matter were perceived to be left on the glass, in the exact places where the foot-hairs had rested. The adhesive fluid appears to pass down through the hollow of the hair, and to be derived from glands which Leydig discovered in the folds of the foot in 1859. A similar adhesive matter appears to be possessed by bugs, by many larvæ, and probably by all insects that climb the stems and the under sides of the leaves of plants.

Flesh-eating no Sin.—Mr. W. Mattieu Williams gives a pointed answer, in the "Journal of Science," to the protests of a vegetarian writer against eating animal food, on the ground that it involves cruelty to living beings. No animals, he says, enjoy a more comfortable life, or are better cared for, than those we keep for food. If we did not eat them, they would be exterminated, for they would not be able to take care of themselves. Yet, in the very sight of the wonderful animal happiness that they enjoy, "the sentimental vegetarians advocate the extinction of all the pastoral bliss that has been a leading theme to poets of all ages." The final killing of them is in accordance with the order of nature, and, if we are to be denounced for it, the Creator must also be denounced for giving life, and at the same time making death one of its necessary conditions. Then, if the killing is wrong, the vegetarian kills on a far more extensive scale, "for the boiling of a cabbage involves the immolation of innocent slugs and caterpillars, and tens of hundreds of thousands of aphides are sacrificed in topping a row of broad beans, to say nothing of the millions of Colorado beetles that have been mercilessly murdered in order that ruthless, selfish man may satisfy his greed for potatoes."

Sun-Worship and the Cross in Ancient America.—Mr. F. L. Hilder, of the Missouri Historical Society, has made a study of a pottery-vessel taken from one of the mounds in the State, and finds that the ornaments upon it represent the sun, figured under four distinct designs. He draws the conclusion, from his examinations, that "the symbolic character of all these devices is so evident that it is impossible to mistake their meaning. They are all well-known emblems of that solar worship which was