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Page:Popular Science Monthly Volume 41.djvu/588

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THE POPULAR SCIENCE MONTHLY.

in her journey across the North American continent, for they excited such intense interest with railway guards, hotel-keepers, etc., that they always insured their mistress civility or a cordial reception.

Wild Plants as Fungus-nurseries.—Prof. B. D. Halsted shows, in a paper on fungi common to wild and cultivated plants, that in many cases diseases are transmitted by spores from one genus or family as well as from one species to another. A bacterium that affects the tomato and potato causes a disastrous form of blight in melons, cucumbers, and squashes. The apple rust that yellows the foliage of the orchard in July is identical with the gynosporangium that produces the galls, swelling out to large size in rainy weather, on cedar trees, and the spores are transmitted in alternation from one tree to the other. It is thus shown by many examples that the evil influences of plant funguses may act at long range. The lesson may be learned from the experiments that "if so much of the smut, rust, mildew, mold, rot, and blight of our cultivated plants is propagated by the wild plants hard by, it may be wise for every crop-grower to pay attention to what is thriving outside of his garden wall."

Skill of Prehistoric Lapidaries.—The most superficial examination of any fairly large collection of stone implements, says Mr. Joseph D. McGuire, in a paper on the materials, apparatus, and processes of the aboriginal lapidary, is calculated to convince the observer that man in his lowest stage of development was well acquainted with the methods of fracture of various stones, and also that he was a most skillful workman. The articles found in burial-places, in caves, and shell-heaps, as well as surface finds, furnish conclusive evidence that man often carried material many hundreds of miles for the purpose of fashioning, at his leisure, objects of personal adornment or domestic utility as well as weapons. The evidence of progress in the manufacture of tools made by man is easy to find: "From the splinter of bone or piece of stone used in the hand to the diamond drill of to-day is an immense advance, but it can be traced, step by step, without a break. The author has himself experimented on the manufacture of stone implements, using tools similar to those of the North American Indians, and beginning with the raw material. The principal work done was the pecking of stone with the stone hammer, and the carving, polishing, rubbing, and boring of stone with the rudest appliances. The result of the experiments goes far to prove that the time required for the manufacture of stone implements by primitive man was very short." If the time occupied by the writer was short, it is fair to conclude that a skillful workman, using the materials which long experience had taught him were the best for his purpose, would accomplish the task in much shorter time. The author, in his paper, records his experiments in pecking nephrite, kersantite, catlinite, obsidian, and basalt, with different hammering material, in drilling and boring, and in hammering copper, the results of which all went to confirm the view he has expressed.

Extermination of Species.—Some of the more obvious causes of the extermination of animals now going on, says Mr. Frederic A. Lucas, in his paper on that subject in the United States National Museum, are to be found in the systematic killing of animals for their various products, the destruction caused by domesticated animals introduced into new countries, and the bringing of wild land under cultivation. These causes most directly affect the larger animals, while smaller creatures are influenced by slighter ones. The erection of telegraph wires has proved destructive to birds, while other birds meet their fate by dashing against the electric lights. The extinction of the rhytina and the great auk, the almost complete extirpation of the bison, and the reduced numbers of the walrus, are good examples of destruction wrought directly by the hand of man; and, besides, there are the still more numerous instances of the very perceptible decrease of animals once abundant. Species used for food, or otherwise of economic value, suffer most; fashion affects some, some are necessarily destroyed for the protection of man and his domesticated animals, and others are killed merely for sport. The passenger pigeons, formerly visiting us by millions, are now unknown in places where they once abounded. Halibut, lobsters, and oysters are getting scarce, and the Atlantic salmon