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SPOROGONIUM

1804

SPRAYING-MIXTURES

multiplicity^ of names for the same body is very confusing at first, but when the terms are learned they are very convenient in designating either the group or method of origin of the spore referred to.

Sporogonium (spd-rd-go'ni-um) (in plants), the leafless sporophyte of mosses, as distinguished from the leafy spororjhyte of ferns and seed-plants. When highly organized, it consists of foot, seta and capsule; and its sole function is the production of spores. See Musci.

Sporophore (spd'ro-for) (in plants), a special branch which bears spores. Used chiefly among the fungi, where special spore-bearing branches arise from the mycelium. See FUNGI.

Sporophyte (spd'rd-fU). In alternation of generations (which see) among plants the generation which bears the asexual spores is the sporophyte, as distinguished from the generation which bears the sex-organs and produces the sexual spore, called the gametophyte. In the mosses the sporophyte is the leafless Sporogonium (which see), consisting chiefly of a spore-case (capsule) on a stalk. In the ferns and seed-plants the sporophyte becomes the conspicuous leafy part of the plant, in fact the whole plant of ordinary observation. It is of interest to note that the sporophyte is essentially sexless, and that to speak of "flowers/' structures produced by the sporophyte, as having sex-organs, is very far from the fact.

Spottsylva' nia Court House, a small villarge in Virginia, 55 miles northwest of Richmond. It is known as the scene of one of the desperate battles of the Civil War, fought between Lee and Grant, May 10, 1864. When Grant was driven back, with terrible slaughter, he wrote to the secretary of war the famous message; "I propose to fight it out on this line, if it takes all summer." On the I2th the attack was renewed, and the next day Lee, suffering from heavy losses, withdrew to an inner line of intrenchments, from which Grant could not drive him but moved around him on his way to Richmond.

Spray'ing=Mixtures are intended to be applied in liquid form by means of spraying-machines to trees, small fruits, vines, flowers and vegetables to prevent the ravages of fungous diseases and insects. Fungicides and insecticides may, in many cases, be applied dry as well as in solution, as the Bordeaux mixture, Paris green etc. Fungicides much used are the popular Bordeaux mixture (q. v,} and ammoniacal solution of copper-carbonate. The latter contains copper-carbonate, five ounces, made into a paste by adding one and a half pints of water, aqua ammonia of 26 degrees strength and 45 gallons of water. This preparation is clear, and is not so easily noticeable on the

plants as are the preparations containing lime. Insecticides for spraying are of two sorts, depending upon the general division of injurious insects into the classes of biting-insects and sucking-insects. Biting-insects, those with jaws for chewing foliage, fruit etc., will also eat the poison on their food; hence the arsenical poisons are most generally used for this class of insects, examples of which are grasshoppers, potato-beetles and other beetles. Sucking-insects have bills that penetrate the plant-tissues, as of the stem, and so are not affected by poisons on the surface. Examples are plant-lice, scale-insects and squash-bugs. They mostly have soft bodies and are fought with soap-kerosene emulsions, designed to coat their bodies and suffocate the insects by excluding the air from the breathing-pores scattered over their skin; for these animals do not breathe through an opening in the head. The lime-sulphur wash is widely used for scale-insects in orchards. The larva or caterpillar stage of flies, beetles, moths and butterflies have both soft bodies and jaws for chewing, and so can be fought by either kind of antidote. The best known of the first class of insecticides are Paris green, London purple and white hellebore. Paris green is composed of copper oxide, acetic acid and white arsenic (arsenious oxide), and should contain at least 50% of the last-named ingredient. Paris green should be mixed with quick-lime to rendef insoluble any free arsenic, which is poisonous to plants, at the rate of one pound of each to each 100 or 300 gallons of water. The mixture should be strained, and constantly stirred while using. London purple is less reliable, on account of the larger amount of soluble arsenic and the variability of its composition. The lime-sulphur wash is composed of unslaked lime 20 pounds, flowers of sulphur 15 pounds and water to make up from 45 to 50 gallons.

The concentrated stock-solution of kerosene-emulsion is composed of hard soap in fine shavings or even of soft soap one half pound, rain-water one gallon, kerosene (sometimes called coal-oil) two gallons. The soap-solution is brought to a boil, poured into the kerosene, and churned vigorously. Dilute for use with 10 to 20 volumes of water. A diluted decoction of tobacco-stems is good for spraying house-plants and garden-vegetables. While not exactly a spraying solution, carbon bisulphid is much used for pests living around the roots of garden-truck. It is a highly inflammable liquid with a very disagreeable odor, and, when poured down a small hole near the base of the plant, it drives away cut-worms and similar pests. Consult Lode-man's Spraying of Plants, Weed's Insects and Insecticides; and bulletins of the state experiment-stations and of the U. S. Dept. of Agriculture.