eastern area, one of instability, culminating, at the close of the Period, in a steady rise of the land and a northward retreat of the Tethys. Nearly the entire Himalaya east of Kashmir became a land surface and remained exposed to denudative forces for so long a time that in places the whole of the Carboniferous, Devonian, and a large part of the Silurian and Ordovician deposits were removed--some thousands of feet in thickness--before resubmergence in the Tethys occurred. Towards the end of the Palaeozoic Age the Aryan Tethys receded westwards, but still covered the Himalaya and was still connected with the European Palaeozoic sea. The Himalayan area (as well as Kashmir) remained submerged in its waters throughout the entire Mesozoic Age. During Cretaceous times the Tethys became greatly extended, indicating a considerable subsidence of northwestern India, Afghanistan, Western Asia, and, probably, much of Tibet. The shallow-water character of the deposits of the Tibetan Himalaya indicates, however, a coast line near this region. Volcanic materials, now poured out, foreshadow the incoming of the great mountain-building epoch of the Tertiary Era. The enormous mass of the Deccan traps, possessing a volume which has been estimated at as much as 6,000 cubic miles, was probably extruded over the Northern Peninsular region during late Cretaceous times. The sea now began to retreat, and by the close of 137 the Eocene, it had moved westward to Sind and Baluchistan. The movements of the Earth's crust were attended by intense volcanic activity, and great volumes of granite were injected into the sediments, followed by dykes and outflows of basic lavas. The Tethys vanished to return no more. It survives in the Mediterranean of today. The mountain-building movements continued into Pliocene times. The Nummulite beds of the Eocene were, as the result, ultimately uplifted 18,500 feet over sea level, a total uplift of not less than 20,000 feet. Thus with many vicissitudes, involving intervals of volcanic activity, local uplifting, and extensive local denudation, the Himalaya, which had originated in the sediments of the ancient Purana sea, far back in pre-Cambrian times, and which had developed potentially in a long sequence of deposits collecting almost continuously throughout the whole of geological time, finally took their place high in the heavens, where only the winds--faint at such altitudes--and the lights of heaven can visit their eternal snows.[1] In this great history it is significant that the longest continuous series of sedimentary deposits which the world has known has become transfigured into the loftiest elevation upon its surface. [1] See A Sketch of the _Geography and Geology of the Himalaya Mountains and Tibet_. By Colonel S. G. Burrard, R.E., F.R.S., and H. H. Hayden, F.G.S., Part IV. Calcutta, 1908. 138