. II, RELICS, into Min. Kingd. 35 



principally, woodf and the bones of mammalia. 

 Plants, as moss, &c., and land and fresh-water 

 shells occur also in the banks of such rivers as 

 afford -a stalactitic tufa. 



d. 16. Local inundations. To these agents, since 

 the commencement of the third period, are perhaps 

 to be referred most superficial accumulations of 

 organic fossils, not deposited in regular strata, and 

 which are not immediately connected with the pre<- 

 sent or former coursef*)* of still existing rivers. 



Partial inundations of fresh waters, in many in- 

 stances, appear to have occasioned the deposits of 

 animal bones, so frequent in the loose earth or soil 

 of those alluvial tracts, which have not, seemingly, 

 originated from the deeper, but more contracted 

 influence of rivers and currents. To sudden inun- 

 dations, also,, are perhaps to be ascribed the destruc- 



f Often forming deltas at the mouths of large rivers. 



ff Extensive depositions of sand, mud, gravel, &c., con- 

 nected with a river, but considerably higher, as well as lower than 

 its present level, may be supposed to have arisen from successive 

 inundations of such rivers ; but, in general, will be found to have 

 originated from deep and wide spread lakes, united by a constant 

 stream or current; the beds of winch lakes have gradually as- 

 sumed the form of alluvial land, and their contracted waters that 

 of a river, now taking its course through the materials deposited 

 in its former state. (For some excellent observations on the forma- 

 tion of alluvial land by modem rivers and lakes, vide Playfair's 

 Illustrations, p. 350.) 



