Page:Popular Science Monthly Volume 17.djvu/873

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The Cotton-Worm Investigation.—The Commission for the investigation of the cotton-worm has been organized under Professor C. V. Riley as chief, and its members have been stationed at different points in the South to make local examinations. Professor J. P. Stillé, of Alabama, and Judge J. W. Jones, will represent the Commission in Texas; Professor R. W. Jones, Dr. E. H. Anderson, and Mr. Lawrence Johnson, in Mississippi; Mr. H. G. Hubbard, Detroit, Michigan, in Florida; Professor Barnard, of Cornell University, will fully study those parts of Louisiana and Mississippi which were neglected in 1878 and 1879 on account of yellow fever; Judge J. F. Bailey, and Mr. James Roane, chemist, will make a special series of experiments in Alabama; Professor J. E. Willet will make experiments in Georgia to test the usefulness of fungus-germs in the destruction of the worm. Maps are to be prepared by Professor Smith, of the State University of Alabama, showing the different cotton regions classified with reference to the hibernation of the insect. Professor Riley, besides having the general superintendence of the work, and advising with his assistants, will collect information and make other preparations for introducing the cultivation of the pyrethrum, which he believes will afford a safe antidote for the worm.

Changes in the Natural Vegetation at San Francisco.—Dr. Herman Behr has published a description of the changes that have taken place in the vegetation of the San Francisco peninsula within the last thirty years. The region was originally distinguished by three types of landscape: the sand-dunes and hills, covered with live-oak, ceanothus, horse-chestnut, and wild cherry, ferns, and common herbs; an open tract of grassy plains, with trees in the ravines, and flowering plants; and a marshy plain, with boggy prairie, covered with a varied growth of bushes and herbaceous plants. Now, the first mentioned type of vegetation, the chaparral, exists still in a few spots; the second, that of the pasture-land, is to be met with still, wherever the distance from the city is considerable enough to protect native vegetation; but the third type has entirely disappeared. In the course of the extension of the city, Australian evergreens and conifers form the Sierra have largely replaced the original trees. "Parallel with this artificial immigration of Australian arborescents, goes on an herbaceous immigration from Europe and Africa." The thistle (Silybum marianum of the Mediterranean region) has invaded both California and South Australia, and, wherever it gets a hold of the soil, all native vegetation disappears. The tree-lupines particularly suffer from its encroachment. Another weed, Cotula coronopifolia, a native of South Africa, well known in Mediterranean Europe, and which has invaded South Australia, does the same work in moist ground that is begun by silybum in more arid tracts. It "has transformed the varied aquatic vegetation of the different places infested by itself into one monotonous green mass with yellow buttons." Dr. Behr regards as significant that these two plants are congenital and belong to one of the most modern orders, of which fossil specimens are found in only the most recent formations, and to which he attributes the vigor of youth.

The Physiological Effects of Tea and Coffee.—Professor Albert B. Prescott, M.D., of the University of Michigan, has published a paper, in "The Physician and Surgeon," on the physiological effects of coffee as compared with those of tea, concerning which the authorities are confusing and little is really known. Inasmuch as the chief constituents of both substances are capable of determination, we ought to be able to declare something, he thinks, as to what there is in common between a medium cup of coffee and an average cup of tea. The effects of tea and coffee, he continues, must be mainly due to the properties and proportions of the alkaloids, tannin, volatile oils, and ordinary food-substances contained in them. As to the alkaloids, no differences have been established between theine and caffeine. In average quantity, the alkaloid forms about one per cent, of the raw coffee-berry, and two or three per cent. of tea. A little of it, but very little, is lost in roasting coffee. The greater