development; but in what measure, at what rate, and through what details of change, is as yet matter of the widest difference of opinion and the liveliest controversy. There are headlong materialists who pronounce man the slave and sport of nature, guided and controlled by the external forces amid which he exists, and who claim that his history may be explained and foretold by means of a knowledge of those forces; when as yet they have not found out even the A-B-C of the modes in which human nature is moulded by its surroundings. These men have their counterparts also among students of language. But, whatever may be hoped from the future, it is certain that at present nothing of value has been done toward showing how linguistic growth is affected in its kind and rate by physical causes. There is no human dialect which might not maintain itself essentially unaltered in structure, though carried to climes very unlike those in which it had grown up, and though employed by a people whose culture and mode of life was rapidly varying; emigration, often assumed to be the chief and most powerful cause of linguistic change, also often appears to exercise a conservative influence. And, on the other hand, a language may rapidly disintegrate, or undergo phonetic transformation, or vary the substance of its vocabulary, without moving from the region of its origin, or becoming the organ of other conditions of human life. When linguistic scholars can fully account for such facts as that the Icelandic is the most antique in form of the idioms of its family, that the Lithuanian has preserved more of the primitive apparatus of Indo-European inflection than any other known tongue of modern times, that the Armenian has become with difficulty recognizable as an Iranian dialect, that the Melanesian, African, and American languages are the most changeful of human forms of speech—then, perhaps, they may claim to comprehend the circumstances that regulate the growth of language.
The variation of language in space, its change from one region to another, is a not less obvious fact than its variation in time, its change from one epoch to another. The earth is filled with almost numberless dialects, differing
