244 INDIAN LANGUAGES INDIAN OCEAN 3 ft. high, with opposite, mucronato leaves, which are smooth or downy, and numerous, many-flowered cymes. The flowers are small, bell-shaped, greenish white, the corolla with five triangular appendages in the throat ; sta- mens five, inserted on the base of the corolla, and slightly adhering to the stigma by their filaments; fruit of two long slender folli- cles with silky tufted seeds. It has a milky juice, and the bark has an exceedingly tough fibre, the use of which by the aborigines for making cordage, fishing nets, &c., no doubt gave it the common name. We know of no extensive experiments in utilizing this fibre, which is whiter and stronger than that of hemp. The root of this plant is sometimes used in medicine, it being powerfully emetic and cathartic in doses of 15 to 30 grains of the powdered dry root, or a similar amount in the form of a decoction; it has been found efficacious in dropsy. It grows in most of the states, and has other local names; in South Carolina it is known as Gen. Marion's weed, as that leader is said to have used it in the diseases of his camp. Another species, A. an- drosamifolium, equally common, is a more spreading plant, with much larger pale rose- colored flowers, and used as a prompt emetic ; it is known as dogbane and bitter-root. INDIAN LANGUAGES, American. See AMERI- CAN INDIANS, LANGUAGES OF THE. INDIAN OCEAN, the third in size of the oceans of the world. It is bounded N. by Asia, N. E. by the Malay peninsula and the Sunda islands, E. by Australia and the meridian of Cape Leeuwen on the 8. W. coast of that continent, S. by the Antarctic circle, and W. by Africa and the meridian of the cape of Good Hope. The south China sea and all the waters south and west of the Philippine isles and New Guinea are sometimes included in the limits of the In- dian ocean ; but they are much more properly apportioned to the Pacific basin, the Sunda islands and Malay peninsula representing the isthmus connecting the northern and southern halves of the continent of Asia- Australia. The southern limit, and the eastern and western S. of the continents of Australia and Africa, are of course entirely artificial. The northern shore of the Indian ocean is deeply indented by the peninsula of India, forming two large bays, the Arabian sea and the bay of Bengal. Two considerable gulfs, or more properly in- land seas, are in communication with this ocean, the Red sea and the gulf of Persia. It is not rich in islands, of which only two, Madagas- car and Ceylon, are of considerable size. The smaller ones constitute mostly archipelagoes, such as the Comoro, Mascarene, Amirante, Sey- chelles, Maldive, Laccadive, Andaman, Nice- bar, Chagos, and Keeling islands, in the tropics, and the Kerguelen, Crozet, and Macdonald isl- ands, in the colder southern part. There are also a few isolated volcanic islands, such as New Amsterdam and St. Paul. Most of the tropical islands are of coral formation ; a few are volcanic with fringing or barrier reefs, such as the Mascarene and Andaman islands. The Asiatic coast is mostly free of coral, but there are some fringing reefs on the coasts of Cey- lon and Madagascar, Africa, and the Red sea. The only important African river falling into this ocean is the Zambesi. Asia contributes the united stream of the Euphrates and Tigris, the Indus, Ganges, Brahmapootra, and Irra- waddy ; Australia almost nothing. The sys- tem of currents is rather complicated, but in its main features resolves itself into a revolv- ing current moving from right to left, as in all the ocean basins of the southern hem- isphere. The equatorial part of it, the S. E. trade current moving from E. to W., is very broad, its middle being about lat. 15 S., but it does not really reach the equator. It strikes the coast of Madagascar, dividing into two branches. The one passing N. of that island bends S. through the Mozambique channel, forming the powerful and warm current of the same name; it is joined again by the 8. branch near the coast of Africa, forming the Agulhas current off the cape of Good Hope, which after barely passing that cape turns back sharply to the south and east, and forms with the antarctic drift the retrograde current in lat. 37 to 42 S. Before reaching Australia it divides into the S. and E. Australian cur- rents, the latter completing the circuit by re- entering the S. E. trade current after giving off branches running into the Java and Flores seas and Torres straits. The N. equatorial cur- rent is overcome by the monsoons, and, under the name of Malabar current, flows westward from October to April, and eastward from April to October. It extends from the coast of Africa around Ceylon into the bay of Ben- gal. A narrow retrograde current has been observed flowing E. across this ocean, nearly under the equator or a little S. of it. The monsoons prevail from its northern limit to lat. 8 S. North of the equator the N. E. mon- soon blows from October to April, the S. W. prevails in the other half of the year; while S. of it the N. W. monsoon blows while the N. E. is blowing on the N. side, and vice versa. Between the limits of lat. 10 and 28 S., the 8. E. trade wind blows from April to October. South of these are the constant N. W. winds, which prevail almost in the same latitudes as in the Atlantic and Pacific oceans. The periods at which these winds change are marked by violent tempests, and the region between lat. 5 and 40 S. is greatly subject to hurricanes. They range usually between lat. 9 and 35 S., extending from Madagascar to the island of Timor; they come generally from the N. E. near Java, and travel S. W. and S., returning again E. The depth of the sea is greatest near the S. coasts of Asia; the Arabian sea is from 2,000 to 2,500 fathoms deep ; the bay of Bengal averages nearly 2,300 fathoms. Opposite the Hoogly river, in the bay of Bengal, is a sudden and deep depression in the ocean bed, called
