and these margins inroll to protect them. Each sporangium is a spore-case upon a slender stalk, and about the case a ring of thick-walled cells is developed, known as the annulus. This ring of cells aids in rupturing the sporangium wall and discharging the spores. When a spore germinates, it develops a minute, flat, green plant known as the prothallium, which bears the sex-organs. The prothallium, therefore, is the gametophyte. By the union of the sex-cells (sperm and eggs) the fertilized egg is produced, which upon germination gives rise to the well-known fern plant, the sporophyte. In the fern, therefore, the alternation of generations is very distinct, the gametophyte and sporophyte being independent of one another, so far as nutrition is concerned.
SORI OF VARIOUS FERNS
Fill'more, Millard, thirteenth president of the United States, was born at Summer Hill, N. Y., on Feb. 7, 1800. In 1819 he began the study of law; in 1823 he was admitted to the Buffalo bar; in 1828 he began his political career. In 1848 he was made Whig vice-president of the United States, and upon the unexpected death of President Taylor, in July, 1850, succeeded to the presidency, which he held until 1853. In 1856 he was nominated for the presidency by the American party, but received the electoral vote of Maryland only. He died at Buffalo, N. Y., on March 7, 1874.
MILLARD FILLMORE
Fil'ter, a vessel arranged for purifying water or other liquids. When water or some other liquid is passed through a substance, the pores or openings of which are too small to allow the solid particles to go through, they, of course, are kept back and the water is cleared. The familiar process of straining is a good illustration of the principle of a filter. For home use, a simple water filter is often made by stuffing a sponge in the hole of a flower-pot, then a layer of pebbles, then one of coarse sand and one three or four inches deep of powdered charcoal, with a second layer of pebbles on top. The pebbles and gravel form the strainers, while the charcoal purifies by absorbing impurities, for which it has a special affinity. The charcoal needs to be renewed occasionally, as it loses its power, and the sand and gravel need cleansing. All filters, therefore, made on this principle, should be easily opened, so as to reach all parts. Water is often filtered, before entering a cistern, by an external filter, or in the cistern itself by means of a division-wall of brick, the water passing through the pores of the bricks. An excellent method of filtering water, devised by Pasteur, consists in forcing the liquid through unglazed porcelain. The process is slow but very effective. Special filters are required for syrups, oils and the like. Oil is passed through bags made of horsehair or canton-flannels; syrups through bags of flannel. Ale, beer and such liquids are difficult to filter, and usually need an addition of some clearing substance, as gelatine. The use of filters in the laboratory is important and extensive. Here the material used for filtering is usually paper which is manufactured for the purpose.
Finch, is the popular name for a large variety of birds, which for the most part belong to the scientific family Fringillidae. The birds called finches are for the most part small, often beautifully colored and not seldom endowed with the gift of song. In the United States and Canada there are said to be 135 kinds of finches; and there, indeed, is no tropical or temperate country in which finches are not found, although some scientists have wrongly excepted Australia, where, in fact, finches are plentiful. The indigo-bird, purple finch, horse-finch, American goldfinch, pine-finch, grass-finch and rosy finch are among the best-known species in this country. Canaries and sparrows are also classed as finches.
Findlay, the county-seat of Hancock County, in northwestern Ohio, in 1885 received a considerable impetus from the discovery of extensive supplies of natural gas. Besides, there are oil, rich deposits of gravel and sand and beds of clay. Of late it has not grown much, though it has a number of industries, including glassworks, pressed-brick works, potteries, foundries, machine-shops, carriage, tool, furniture, and wooden-implement factories, rail and rolling-mills and an oil-refinery. The city has some fine civic buildings and a number of churches; it contains Findlay College and has excellent public schools. It is served by three railroads, and has all the adjuncts of a modern city. Population 14,858.
