Introductory.—In this writing I wish to call attention to certain features in the distribution of mountains which seem to me to throw light on the conditions which lead to the development of continents, and, as the points to be set forth concern a considerable, range of phenomena, I shall state them briefly, with the expectation that in some other form of publication the chance may be offered for more extended presentation.
Limitations as to Position of Mountains.—Mountains appear to be limited to the continents or to large islands which are more or less continental in their relations. This is shown by the fact that the surfaces of the greater oceans are essentially destitute of islands which we can suppose to be mountain-tops which have attained the surface of the water. All the thalassic islands, in a word, are volcanic masses or have been brought to the surface by . . .