J. D. Dana—Results of the Earth's Contraction, etc. 448 
well as a rise of water about the continents from the diminu- 
tion in the ocean's depth; and when the oceanic geanticlinal 
flattened out again through subsidence, the subsiding crust 
would naturally produce a reverse movement along one or both 
continental borders. 
From the various considerations here presented, derived from 
both the continental and oceanic areas, it is apparent that the 
earth has exhibited its oneness of individuality in nothing more 
fundamentally and completely than in the heavings of its con- 
tracting crust. are 
The subjects of metamorphism, the earth’s interior, igneous 
eruptions and volcanoes remain for discussion. In addition I 
propose to consider the steps in the origination of the conti- 
hental plateaus and oceanic basins, and also present some facts 
bearing on the general nature of the infra-Archzan crust, that is, 
the part below the earth’s superficial coatings. 
* Author’s Rep. Geol. Wilkes U. 8. Expl. Exped., 4to, 1849, p. 399; and Corals 
and Coral Islands, 8vo, 1872, p. 329. 
+ Rep. Geol. . 399; Corals and Coral Islands, p. 328. 
Am. Jour, Scr.—Tuirp Sertes, Vou. V, No. 30,—June, 1873, 
28 
