Page:Encyclopædia Britannica, Ninth Edition, v. 12.djvu/715

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IDA—IDA
697

rate it signified one in the plumage of which yellow or green predominated, and hence Brisson did not take an unhappy liberty when he applied it in a scientific sense to some birds of the New World of which the same could be said. These are now held to constitute a distinct Family, Icteridce, intermediate it would seem between the BUNTINGS (vol. iv. p. 525) and STARLINGS (q. v.) ; and, while many of them bear the vulgar name of Troopials (the English equivalent of the French Troupiales, first used by Brisson), others are known as the American GRACKLES (vol. xi. p. 26). The typical species of Icterus is the Oriolus icterus of Linnaeus, the Icterus vulgaris of Daudin and modern ornithologists, an inhabi tant of northern Brazil, Guiana, Venezuela, occasionally it is said visiting some of the Antilles and of the United States, but without much apparent proof. Thirty-three species of the genus Icterus alone, and more than seventy others belonging to upwards of a score of genera, are recognized by Messrs Sclater and Salvin (Nomendator, pp. 35-39) as belonging to the Neotropical Region, though a few of them emigrate to the northward in summer. It would of course be impossible here to dwell upon them, but Cassicus and Ostinops may perhaps be named as the most remarkable. They are nearly all gregarious birds, many of them with loud and in most cases, where they have been observed, with melodious notes, rendering them favourites in captivity, for they readily learn to whistle simple tunes, which are admirably reproduced by their clear voice. Some have a plumage wholly black, others are richly clad, as is the well-known Baltimore Oriole, Golden Robin, or Hangnest of the United States, Icterus baltimore, whose brightly contrasted black and orange have conferred upon it the name it most commonly bears in North America, those colours being, says Catesby (Birds of Carolina, i. p. 48), the tinctures of the armorial bearings of the Culverts, Lords Baltimore, the original grantees of Mary land, but probably more correctly those of their liveries. Tlie most divergent form of Irteridte seems to be that known in the United States as the Meadow-Lark, Sturnella mayna or S. ludoviciana, a bird which in aspect and habits has considerable resemblance to the Larks of the Old World, Alatididce, to which, however, it has no near affinity, while Dolichonyx oryzivorus, the Rice-bird, with its very Bunting- like bill, is not much less aberrant. (A. N.)

IDAHO, a north-western territory of the United States, was originally a part of Oregon, from which it was separated in 1863. It lies on the Pacific slope, with the exception of a small portion in its south-eastern corner, which is drained into the Great Salt Lake of Utah. It is bounded on the N. by British Columbia and N.E. by Montana; on the E. by Wyoming ; on the S. by Utah and Nevada /and on the W. by Oregon and Washington. The boundaries are the meridians (111 and 117 W. long.) and the 42d and 49th parallels of N. lat., except that in the N.E. the Bitterroot range separates the territory from Montana, and the Snake river forms part of the western limit. The area of the territory is imperfectly known, but may be set down approximately at 86,300 square miles. The mean elevation is about 4700 feet. The lowest point, which is on Snake river, at the mouth of the Clearwater, is about 1000 f:et above the sea, while the highest mountains rise nearly to 1 0,000 feet. The surface is very diversified ; the northern portion is largely mountainous, with several fine broad valleys. In the southern portion a large area within the

Vireo may be readily explained by its being a very common and con spicuous bird, as well as one which varied in plumage according to age. and sex (cf. ORIOLK). Owing to its general colour, Chloris was in time transferred to the GREENFINCH (vol. xi. p. 165), while the names Galbula, Parra, and Vireo have since been utilized by ornithologists (cf. JACAMAR and JACANA).

great bend of the Snake river is occupied by an immense plain of basalt. South of the Snake the country is an alternation of broad valleys and narrow abrupt mountain ranges.

The principal mountains are the Bitterroot and Salmon River chains, with their spurs and subordinate ranges. They attain a height of from 8000 to nearly 10,000 feet. The Snake River plain lies south of these mountains, ex tending east and west nearly across the territory. This is a field of basalt, seamed and crevassed, with little vegeta tion, and that consisting principally of Artemisia. The soil here is a shifting sand; and there is little surface water, as the streams sink and flow underneath.

The principal river is the Snake, the south fork of the Columbia. It is a rapid stream with numerous falls, three of which, the American, Shoshone, and Salmon or Fishing, are very considerable. It is navigable only in its lower course. Several of the branches of the Snake, the Salmon, Clearwater, and Spokane, are large streams, but are not navigable, and are of value only for irrigation and mining purposes.


Map of Idaho.


The climate, like that of other portions of the north western United States, is characterized by great aridity of atmosphere and slight rainfall. In the south the aridity is such that large areas are almost desert; but in the mountainous regions of the north the rainfall is much greater, and agricultural operations can be carried on to some extent without irrigation. The northern part, being principally mountainous, is covered with forests of conifers, chiefly species of pine, spruce, fir, and tamarack. In the open valleys the vegetation consists mainly of the various kinds of grasses known collectively as "bunch grass."

On the Snake River plains there is little vegetable growth