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Page:Popular Science Monthly Volume 54.djvu/884

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860
THE POPULAR SCIENCE MONTHLY.

answers, eight hundred and ninety-seven of which came from the United States and the rest from the Canadian provinces. These reports showed that in many localities, particularly in the East and South, but little attention is paid to keeping varieties pure, and many farmers use mixed, unknown, or local varieties of ordinary merit for seed. In New England but little grain is grown from sowing, owing to the cheapness of Western grain, and wheat is rarely reported. Oats are now mostly sown from Western seed, and the resulting crop is mown for hay, while most of the corn is cut for green fodder or silage. On certain fine lowlands—as, for example, in the Connecticut Valley—oats, and more especially corn, are often grown for grain. While reports on most of the cereals were rendered from the lower austral zone, or the region south of the Appalachians and the old Missouri Compromise line, this region, except where it merges with the upper austral or the one north of it, is apparently outside the area of profitable cultivation of wheat and oats. In Louisiana and most of the other parts of the lower austral, except in northern Texas and Oklahoma, wheat is almost an unknown crop. The warm, moist climatic conditions here favor the development of fungous diseases to such a degree that the plants are usually ruined or greatly injured at an early stage of growth. In Florida, as a rule, cereals are rarely cultivated except on the uplands at the northern end of the State. In a general way, corn and wheat are most successfully grown in the upper austral zone, or central States, while oats are best and most productive in the transition zone (or northern and Lake States and the Dakotas), or along the border of the upper austral and transition. The gradual acclimation of varieties of cereals, through years of selection and cultivation, has gone so far, however, that some varieties are now much better adapted to one zone than to another.

 

Spanish Silkworm Gut.—The business of manufacturing silkworm gut in Spain is a considerable industry. The method of preparation is thus described in the Journal of the Society of Arts: After the silkworm grub has eaten enough mulberry leaves, and before it begins to spin, which is during the months of May and June, it is thrown into vinegar for several hours. The insect is killed and the substance which the grub, if alive, would have spun into a cocoon is drawn out from the dead worm into a much thicker and shorter silken thread, in which operation considerable dexterity and experience are required. Two thick threads from each grub are placed for about four hours in clear cold water, after which they are put for ten or fifteen minutes in a solution of some caustic. This loosens a fine outer skin on the threads, which is removed by the hands, the workman holding the threads in his teeth. The silk is then hung up to dry in a shady place, the sun rendering it brittle. In some parts of the country these silk guts are bleached with sulphur vapor, which makes them beautifully glossy and snow-white, while those naturally dried have a yellowish tint. The quality of the gut is decided according to the healthy condition of the worm, round indicating a good quality and flat an inferior one.

 

The Nests of Burrowing Bees.—Prof. John B. Smith, having explained to his section of the American Association a method which has been successfully applied, of taking casts in plaster of Paris of the homes of burrowing insects, with their branchings, to the depth of six feet, described some of the results of its application. Bees, of the genus Calletes, dig vertically to the depth of eighteen inches or more, then burrow horizontally from two to five inches farther, and construct a thin, parchmentlike cell of saliva, in which the egg is deposited, with pollen and honey for the food of the larva. They then start a new horizontal burrow a little distance from the first, and perhaps a third, but no more. The vertical tubes are then filled up, so that when the bees come to life they must burrow from six to twentyfour inches before they can reach the surface. Another genus makes a twisted burrow; another makes a vertical burrow that may be six feet deep. About a foot below the surface it sends off a lateral branch, and in this it excavates a chamber from one to two and a half inches in diameter. Tubes are sent down from this chamber, as many perhaps as from six to twenty together, and these are lined with clay to make