Page:Popular Science Monthly Volume 37.djvu/737

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Dr. J. Walter Fewkes has described in The American Naturalist some specimens of excavations made in rocks by sea-urchins, which he observed at Grand Manan, New Brunswick. Other places where such excavations have been found are Florida, the West Indies, Panama, California, the Mediterranean, coasts of the British Isles and France, and Australia. The holes, which are occupied by the animals, are never deeper than the thickness of the urchins' bodies, and are very smooth. It has been suggested that the holes are worn by the spines of the animal, or perhaps chiseled out by its teeth, and Dr. Fewkes adds that perhaps motions of the animals caused by waves aid the process of erosion. Another recent paper by Dr. Fewkes describes some Californian Medusæ, with plates.

A writer in the North China Herald of Shanghai asserts that the climate of Asia is growing colder, and its tropical animals are slowly retreating southward. In proof of this he quotes evidences, historical and referential, of the former existence of elephants, tigers, and leopards in China. Tigers and leopards are, however, not yet extinct in China, and are common enough in Corea. The bamboo, it is said, formerly grew naturally in parts of the country where it now has to be taken care of.

The Central Park Menagerie had 907 animals on exhibition during 1889, representing 242 species, 164 genera, and 71 families. The most notable additions to the collection were, by gift or exchange, a three-toed sloth, an American civet-cat, very seldom seen alive in zoological collections, and a pair of young elks; and by birth a sea-lion, two nylghaie antelopes, and one hippopotamus. The last died four days after birth. The principal cause of death among the animals was congestion of the lungs.

"To get rid of the timber," the answer given to an inquiry from the Michigan State Forestry Commission respecting the timber policy of the State of Arkansas, is made by Mr. William Little the text of a letter to the Montreal Board of Trade on the importance of preserving the timber. The interests of the United States and Canada in this matter are substantially the same. Having shown that the forests of the continent are on the verge of extinction, and having pointed out the lesson that the people of the United States will shortly be taught, if our political bosses impose a restrictive duty on Canadian lumber, the author warns his countrymen that if they continue stocking our saw-mills with logs taken from this already too scanty supply, and keep warring on their forests, they will soon be able to "get rid of their timber," and to get rid at the same time of the most valuable property they ever had or may ever expect to have in their country.

A group of papers from the Journal of Mycology on The Treatment of Plant Disease is published in a separate pamphlet by Jhe Section of Vegetable Pathology of the United States Department of Agriculture. The relation of Mr. A. A. Crozicr's experiments on the effects of certain fungicides upon the vitality of seeds shows that soaking in blue vitriol and in copperas tends to retard germination. Prof. Byron D. Halsted contributes an investigation of the scald and gall fungus of the cranberry. Other papers, by different authors, relate chiefly to other fungoid diseases and to the qualities of fungicides.

Six scholarships have been established in the Missouri Botanic Garden to provide six years' courses of theoretical and practical instruction for young men desirous of becoming gardeners.

Although there is a wide enough field for platinum-plating in the making of various kinds of instruments and apparatus, such great difficulties attend the process that it has never been made a commercial success. In the first place, the metal tends to separate from its salts in the spongy form instead of forming a firm, hard coating. Then, too, platinum is so insoluble that plates of it can not be used for keeping up the strength of the bath. Mr. William H. Wahl has communicated to the Franklin Institute a method of depositing platinum by which these difficulties are largely avoided. For keeping up the strength of the bath he uses platinum hydrate, which dissolves freely in aqueous solutions of the alkaline hydrates, forming platinates. These platinate solutions conduct electricity freely and yield bright, reguline, and adherent deposits of the metal.

On the French coast of Croisic may be seen thousands of little sea-urchins ensconced in cavities in the granite rock, the openings of which are too small to permit their ingress or exit. The animals, it is not doubted, make and widen the holes for themselves, but the question how has not been answered. Chemical solution of the rock does not seem possible, as no sufficiently strong acid is found in the animal. M. John has recently explained it by mechanical action. With the so-called lantern of Aristotle, a curious formation with which the animal breaks up the hard substances on which it feed?,

it probably bites the rock; the sucker-feet are attached, and a rotary motion is imparted to the body, the spines and the lantern slowly wearing down the surface of the rock.

A report of the first systematic attempt to determine whether beets can be raised successfully for sugar in Nebraska is given in Bulletin No. 13 of the State Agricultural Experiment Station. Beets had been raised