﻿96 Correspondence — Mr. Searles V. Wood,jun. 



seams, and tlie whole of the Hampshire Eocene is connected with 

 the delta of a great river which persisted throughout the accumula- 

 tion of the various beds, which aggregate to upwards of 200 feet in 

 thickness. This river evidently flowed from the west, through a 

 district of which the low ground had a tropical climate ; but like 

 some tropical rivers of the present day, such as the Brahmaputra, 

 the Megna, the Ganges, etc., it was probably fed by tributaries 

 flowing from a mountain region supporting zones of vegetation of 

 all kinds from the tropical to the Arctic, if during the Eocene period 

 "vegetation such as the present Arctic had come into existence, of 

 which we have as yet no evidence. Torrential floods may have 

 swept the remains of vegetation from the temjDerate zones of this 

 region into tributaries that conveyed it into the main river before it 

 was decayed or water-logged, where it became intermingled with 

 the remains of vegetation which grew in the tropical low ground 

 skirting the main stream, so that both sank together into the same 

 mud and silt. 



Assuming, therefore, that the determinations of these extra-tropical 

 forms of vegetation are well founded, we have in the case in 

 question no difficulty in discovering those elevated regions from 

 which, in the way suggested, such forms may have come, for Mr. 

 Judd, in describing (Quart. Journ. Geol. Soc, vol. xxx. p. 220) the 

 ancient volcano of Mull, which lies about 400 miles N.N.W. of 

 Hampshire, has shown that it was in full activity during the 

 Eocene and Miocene periods, and possessed a dimension much 

 exceeding that of Etna at the present day ; and that, though from 

 denudation and collapses, the greatest elevation to which any of its 

 remnants now reach is only 3172 feet, yet that in Eocene and 

 Miocene times its elevation must in all probability have greatly 

 exceeded that of Etna, which is nearly 11,000 feet. 



Nearer, however, than this, and between 100 and 200 miles only 

 N.W. from Hampshire, we have in Wales a mountain region, the 

 summits and upper zones of which (if we take into consideration the 

 considerable depression which the western side of the British Isles 

 must have undergone coincidently with the upheaval of the Eocene 

 sea-bed in the south-east of them, and make some allowance for the 

 action of subaerial denudation) would have had an elevation sufli- 

 cient to support a temperate and extra-tropical vegetation during 

 the Eocene period synchronously with the growth of tropical forms 

 in the low ground, and have furnished to the sediment of the 

 principal river the remains of various forms of vegetation, which, 

 according to the elevation of their source, departed more or less from 

 those of tropical character which clothed the banks of the streams 

 flowing through that low ground. Searles V. Wood, jun. 



Medals and Funds to be Awarded by the Council of the 

 Geological Society, February 16th. — Four Medals will be 

 awarded at the ensuing Anniversary Meeting of the Geological 

 Society: the " Wollaston " (Gold Medal), the '' Lyell," the " Mur- 

 chison," and the "Bigsby" Bronze Medals; and £116 18s. Id. 

 in funds. 



