The discussion on the origin of the Himalayas, started by Sir T. H. Holland's review of Colonel Burrard's memoir, appears to have been led, by the concluding sentence of that review, into an unprofitable channel; for alike in the review and in the succeeding articles by Mr. Fisher and Colonel Burrard it seems to have been accepted that only two theories are applicable, firstly, Mr. Fisher's discussion of the theory of the disturbed tract contained in chapter x of the first and chapter xiii of the second edition of his Physics of the Earth's Crust, and, secondly, that developed by Colonel Burrard. Further, it is assumed that the former is dependent on the hypothesis of a fluid earth and the latter such as should follow from the hypothesis of a solid, highly heated, and cooling globe: the connexion, in either case, being so close that the acceptance of one or other hypothesis, of the constitution of the earth, necessitates the acceptance of one and the rejection of the other of the theories of the origin of the Himalayas.