LUBBOCK ON THE ANTIQUITY OF MAN. 261 



follows : — " Ell efFet ropinion tie la plupart des geologues est que les 

 " cataclysmes diluviens ont eu pour causes predominantes de fortes 

 " oscillations de I'ecorce terrestre, des soulevements de montagnes 

 " au milieu de I'ocean, d'ou seraient resultees de grandes erosions. 

 " Par consequent les puissants courants d'eau marine, auxquels on 

 " attribue ces erosions diluviennes, auraient du laisser sur les conti- 

 " neiits des traces autlieutiques de leur passage, tels que de nombreux 

 " debris de coquilles, de poissons et autres animaux marins analogues 

 " a ceux qui vivent actuellement dans la mer. Or, aiiisi que M. 

 " Cordier I'a fait remarquer depuis longtemps a son cours de geologic, 

 " rien de semblable ii'a ete constate. Sur tons les points du globe 

 " oil Ton a etudie les depots diluviens, on a recoiinu que, sauf quelques 

 " rares exceptions tres contestables, il n'existe dans ces depots aucun 

 " fossile marin : ou bien ce sont des fossiles arraches aux terrains 

 " preexistants, dont la denudation a fouriii les materiaux qui com- 

 " posent le diluvium. En sorte que les depots diluviens semblent 

 " avoir eu pour cause des plienomenes meteorologiques, et paraissent 

 " etre le resultat d'immenses inondations (Teaio douce, et uoii d'eau 

 " marine, qui, se precipitant des points eleves vers la mer, auraient 

 " denude luie graiide partie de la surface du sol, balaye la generalite 

 " des etres organises et pour aiiisi dire iiivele, coordonne les bassins 

 " liydrographiques actuels."* (See also D'Arcliiac, 1. c. passim). It is 

 unnecessary for me to point out how entirely these views difter from 

 the one here advocated, and which we owe mainly to the persevering 

 researches of Mr. Prestwich. Such cataclysms as those supposed by 

 Mr. D'Orbigny, and many other French Greologists, even if admitted, 

 would not account for the results before us. "We have seen that 

 the transport of materials has not followed any single direction, but 

 has in all cases followed the lines of the present valleys, and the 

 direction of the present waterflow ; that the rocks of one valley are 

 never transported into another ; that the condition of the loess is 

 irreconcileable with a great rush of water ; that the mammals and 

 molluscs are the same throughout the period ; while, finally, the 

 perfect preservation of many of the most delicate shells is clear proof 

 that they have not been subjected to any violent action. 



We must, moreover, bear in mind that the gravels and sands are 

 themselves both the proof and the results of an immense denudation. 

 In a chalk country, such as that through which the Sonime flows, each 

 cubic foot of flint, gravel or sand, represents the removal of at the very 

 least twenty cubic feet of chalk, all of which, as we have already seen, 

 must have been removed from the present area of drainage. In 

 considering, therefore, the formation of these upper and older gi'avels, 

 we must not picture to ourselves the original valley as it now is, but 

 must, in imaguiation, restore all that immense mass of chalk which 

 has been destroyed in the formation of the lower level gravels and 

 sands. Mr. Prestwich has endeavoured to illustrate this by a dia- 



* C. D'Orbigny, Bui. Geo. 2nd ser. V. xvii. p. 66. 



