On the Svhmcrgence ofContments. 67 



that could be considered as representing an old continental sur- 

 face, that might have been long covered with terrestrial vegeta- 

 bles, and inhabited by land animals, before being enveloped by 

 marine deposits. He shews, that he has in vain sought the 

 traces of old continental surfaces in contact with the marine and 

 fresh water formations, which alternate in several parts of France, 

 Germany, and England. He unfolds the reasons for thinking 

 that the remains of vegetables, which are sometimes found in a 

 vertical position in sandstone of the coal formation, owe this po- 

 sition only to chance. The presence of remains of mammifera, 

 whether in the diluvian strata properly so called, or in caves an- 

 terior to these strata, appears to him to afford no better evidence 

 that the sea has overwhelmed a soil previously inhabited ; and 

 he ultimately arrives at the conclusion, that the countries which 

 are occupied by alluvial and sedimentary deposits, were covered 

 by the waters during the whole time that these deposits required 

 for their formation. 



The author then carefully enumerates the principal circum- 

 stances which characterize the formation of the deposits which 

 take place in our own days in lakes, at the mouths of rivers, on the 

 shores of the ocean, and in all the parts of its basin which have 

 little depth. Among these deposits, he distinguishes those 

 which result from more or less rapid currents, and those which 

 proceed from quiet precipitations; those which belong to the 

 shores, and those formed in the open sea. He calls to mind the 

 fact, that rivers frequently carry out to great distances continen- 

 tal organic remfdns of all descriptions, and that the waters of the 

 sea, accidentally raised from their basin, sometimes make mo- 

 mentary irruptions over surfaces of great extent, which are com- 

 monly occupied by marshes, lagoons, and lakes, the bottom of 

 which is incontestably formed by deposits filled with fluviatile 

 and terrestrial organic remains. He makes various remarks up- 

 on the nature of the moUusca, which live isolated or in families, 

 near the shores, or at a distance from them. Lastly, he shews, 

 that, by the concurrence of presently existing causes, the English 

 Channel (La Manche) ought to contain alternations of strata ana- 

 logous to those which constitute the lower part of many tertiary 

 formations ; that >verc the level of the' sea lowered twenty-five 

 fathoms, this strait would be changed into a vast lake ; and that 



