Page:The New International Encyclopædia 1st ed. v. 14.djvu/831

* OAR-FISH. 705 OAT. The body is much chjiiiiatoil and at the same time attenuated and compressed. The dorsal fin ex- tends the wliole lengtli of the hack, and the ven- tral lins consist only of a single long ray and 7255?2?Z?2K.--. N" M^ BANEs's OAR-FI8Q {Regalecus Banksi). often are dilated at the end; the movith is small. Specimens 20 feet long have been taken. The anterior portion of the dorsal fin is produced so as to suggest a mane, and it is probable that most of the so-called sea serpents are referable to this fish. The only species {Regalecus Banksi) is cosmopolitan in its distribution. Compare I'xii ORX-Fisir. OAS, o-jis'. A town of Southern Luzon, Phil- ippines, in the Province of Albay. It is situated on the main road, 16 miles northwest of Albay (Jlap: Philippine Islands, H 6). Oas is the centre of an important hemp-growing region, and carries on <i considerable river trade. Popula- tion, in 180e, 15,987. OASIS, (')'ff-sis (Lat., from Gk. oaai;, oasis; <"onnected with Copt, ouahe, dwelling-place, oasis, from oiiih. to dwell). A fertile place in a desert. As the barren condition of most deserts results from small rainfall, the presence of oases depends upon the occurrence of springs or streams which can be utilized for irrigation. In the Sahara there are mountains of sufficient height to pro- voke precipitation, and the neighboring lowlands may thus receive sufficient water to support vege- tation. A water supply is frerjuently obtained also from wells located at considerable distances from regions of precipitation. A combination of soil that holds water, but prevents evaporation, is sometimes found, and greatly favors the for- mation of oases. See Artesi.: Wells. OAT (AS. ute, of unknown derivation). Numerous species of plants of the genus Avena, belonging to the order Oraminefe, or grasses. The commonest species, characterized by loose pan- icles instead of spikes of flowers as in the case of wheat, barley, and rye. is of unknown nativity, but it is believed to have l)een derived from a single jireliistoric form, prolialily a native of eastern temperate Kurope and of Tatary. The common cultivated varieties of oats are classified under two groups, or types, based on the form of the panicles, namely, common oats with ojien spreading panicles, and Tartarian oats M'ith contracted one-sided panicles. These types are sometimes considered as distinct species, the former as Aveini snlini. the latter Arena oricn- tulis. In general the varieties of pats differ in the color and thickness of the husk, the form of the grain, the length of the straw, and the time of ripening. In color they are usually yellow, white, or black. There are a number of species of but little importance, such as wild oats (Arena fatua), which is generally considered as a weed, but has become an abundant and valual)le wild pasture grass in California; bristle-pointed oats (Avetia strigosa), also a weed, but some- times grown for green fodder; animated oats {Ai-eyia sterilis), so named from the fact that when the dry awn absorbs moisture it untwists and thus gives motion to the grain; and .short oats {Arena hreris), cultivated for its grain at high elevation in the mountainous parts of France and Spain, ripening where other kinds do not, and also grown as a forage ])lant in other parts of Europe. See Colored Plate of Cereals. The oat is a hardy plant, especially well adapted to temperate climates, and is not culti- vated to any great extent in hot countries. It is extensively grown in the United States and Canada, in Great Britain, and in the countries of Northern Europe. It succeeds best in a cool, moist climate, but it will grow quite well in warmer regions if the soil is sufficiently moist. In hot and diy regions it grows very poorly. Oats are not a fastidious crop as to the char- acter of the soil, and will grow on light or heavy soils, but are intolerant of excess of water. The seed-bed for oats is prepared about the same as for wheat and barley, but not quite so deep. In the Eastern United States the land is usually plowed before the oats are sown, but in the Western States, especially in new and fertile regions, they are frequently sown on corn land without plowing and covered with a corn cul- tivator or disk harrow, the surface of the soil being then smoothed with an ordinary harrow. When sown on unjilowcd land oats are always broadcasted, and on plowed ground the practices of both drilling and broadcasting prevail. On the whole, the greater portion of the crop is broad- casted. From two to three bushels of seed is the usual quantity sown per acre, Oats are sown in the spring and in the fall. Spring-sown oats represent the bulk of the crop, while fall-sown or winter oats are limited to southern localities. When sown as early in the spring as possible the crop has the advantage of making most of its growth during the cooler part of the season, which is best adapted to its development. In mn-thern latitudes it ripens in ninety days, or even less, but in southern regions a longer time is required. From forty to sixty bushels per acre is con- sidered a good yield, but much larger yields are sometimes obtained. Russia and the United States are the greatest oat-producing countries of the world. In 1800 the United States produced 7flll. 177.71.'? liusliels. The average yield per acre in the United States for the years' ISilO to IS!)!), inclusive, was about 26.14 bushels. The highest average yields, about 40 bushels per acre, are produced by Germany and Great Britain. The oat. although quite free from insect enemies and plant diseases, is subject to rust and loose smut in a way similar to wheat, (See RusT; Smuts.) Early maturing varieties are tisually preferred because they often ripen before rust heeonies injurious to the crop, and, on account of being