In this connection I would like to conclude the present chapter by giving prominence to an interesting and ingenious hypothesis, which has been suggested by Dr. Hale on the basis of the facts just alluded to. In order that the merits of this suggestion may be appreciated, it is desirable to remind the reader that the languages now spoken by the native tribes of the American continent present so many and such radical differences among themselves, that, with regard to a large proportion of them, philologists are unable so much as to suggest any philological classification. Thus, to quote Professor Whitney, “as regards the material of expression, it is fully confessed that there is irreconcilable diversity among them. There are a very considerable number of groups, between whose significant signs exist no more apparent correspondencies than between those of English, Hungarian, and Malay; none, namely, which may not be merely fortuitous.”[162] And, what is most curious, these immense differences may obtain between neighbouring tribes who are to all appearance ethnologically identical—as, for instance, the Algonkin, Iroquois, and Dakota groups. Moreover, this diversity of language-structure in some cases goes so far as to reach the very roots of language-growth; “the polysynthetic structure does not belong in the same degree to all American languages: on the contrary, it seems to be altogether effaced, or originally wanting, in some.”[163] Nay, even the isolating type of language has gained a footing, and this in its properly monosyllabic and uninflective form. Such being the state of matters on the American continent (and also, though to a lesser extent, in the Southern parts of the African), Dr. Hale suggests the following hypothesis by way of explanation. To me it certainly appears a plausible one, and if it should eventually be found to furnish a key for unlocking the mysteries of language-growth in the New World, it would obviously become available as a sufficient explanation of radical diversities of language elsewhere.