make it a sufficient and convincing evidence of genetic unity; but it is evidently of a less direct and unmistakable character than material identity, and requires for its estimation a wider range of knowledge, a more acute insight, and a more cautious judgment. If two languages agree in the very material of which their words and apparatus of grammatical inflection are composed, to a degree beyond what can possibly be regarded as the effect of accident or of borrowing, the conclusion that they are akin is inevitable; nothing but community of linguistic tradition can explain such phenomena: but agreement in the style only in which words are composed and thought expressed admits of being attributed to causes other than historical—to equality of mental endowment, of intellectual force and training. We may look hopefully forward to the time when linguistic science shall have reached such a pitch of perfection, shall have so thoroughly mastered the infinitely varied phenomena of universal human language and traced out their causes, that she shall be able to separate with certainty the effects of ethnic capacity from those of transmitted habit: but that time has certainly not yet come; and, as the value of morphological accordances as evidence of genetic connection has hitherto been repeatedly overrated, so it will long, and always in unskilful or incautious hands, be peculiarly liable to a like mistreatment.
We have already had occasion to refer to and describe some of the principal structural peculiarities which are illustrated in the variety of human tongues; but it will be worth while here to bestow a few words farther upon them, and upon the systems of morphological classification to which they have served as foundation.
The languages of mankind have been divided into two grand classes, the monosyllabic (otherwise called isolating, or radical) and the polysyllabic (or inflectional). To the former belong the tongues of China and Farther India, with their relatives in the same quarter of Asia, and perhaps one or two idioms in other parts of the world. In them there is a formal identity of root and word; none of their vocables are made up of radical and formative elements, the one giving
