COMMENCEMENT OF PRESENT SPECIES. 75 



sion, extensively, if not universally, destroyed. Nor does 

 the idea of its universal destruction seem the less plausi- 

 ole, when we remark, that none of the species of land 

 animals heretofore discovered can be detected at a subse- 

 quent period. The whole seem to have been now changed. 

 Some geologists appear much inclined to think that there 

 was at this time a new development of terrestrial animal 

 life upon the globe, and M. Agassiz, whose opinion on 

 such a subject must always be worthy of attention, speaks 

 all but decidedly for such a conclusion. It must, how- 

 ever, be owned, that proofs for it are still scanty, beyond 

 the bare fact of a submersion which appears to have had 

 a very wide range. I must therefore be content to leave 

 this point, as far as geological evidence is concerned, for 

 future affirmation. 



There are some other superficial deposits, of less con- 

 sequence on the present occasion than the diluvium — 

 namely, lacustrine deposits, or filled- up lakes ; alluvium, 

 or the deposits of rivers beside their margins ; deltas, the 

 deposits made by great ones at their efflux into the sea ; 

 peat mosses ; and the vegetable soil. The animal remains 

 found in these generally testify to a zoology on the verge 

 of that which still exists, or melting into it, there being 

 included many species which still exist. In a lacustrine 

 deposit at Market- Weighton, in the vale of York, there 

 have been found bones of the elephant, rhinoceros, bison 

 wolf, horse, felis, deer, birds, all or nearly all extinct 

 species ; associated with thirteen species of land and fresh 

 water shells, *' exactly identical with types now living 

 in the vicinity." In similar deposits in North America, 

 are remains of the mammoth, mastodon, buffalo, and other 

 animals of extinct and living types. In short, these su- 

 perficial deposits show precisely, such remains as might 

 be expected from a time at which the present system of 

 things (to use a vague but not unexpressive phrase) ob- 

 tained, but yet so far remote in chronology as to allow ot 

 the dropping of many species, through familiar causes, in 

 the interval. Still, however, there is no authentic or sa- 

 tisfactory instance of human remains being found, except 

 in deposits obviously of very modern date ; a tolerably 

 strong proof that the creation of our own species is a com- 

 paratively recent event, and one posterior (generally 

 speaking) to all the great natural transactions chronicled 

 by geology. 



