268 PALEONTOLOGY : FOSSIL ORGANIC REMAINS. 



a field filled with the bones of Mastodon (Carapo da 

 Gigantes), in which I have had careful excavations 

 made. ( 315 ) The bones found on the table lands of 

 Mexico belong to true elephants of extinct species. The 

 minor ranges of the Himalaya, the Sewalik hills, which 

 Major Cautley and Dr. Falconer have examined with so 

 much zeal, contain, besides numerous Mastodons, the Siv*- 

 therium, and the gigantic land tortoise (Colossochelys), 

 more than twelve feet in length and six in height, as well 

 as remains belonging to still existing species of elephants, 

 rhinoceroses, and giraffes. It is worthy of notice, that these 

 fossils are found in a zone which still enjoys the same tro- 

 pical climate which is supposed to have prevailed at the 

 period of the Mastodons. ( 316 ) 



Having thus viewed the series of inorganic formations 

 which compose the crust of the earth in combination with 

 the animal remains interred in them, we have still to consi- 

 der the vegetable kingdom of the earlier times, and to trace 

 the epochs of the successive floras which have accompanied 

 the increasing extent of dry land, and the progressive modi- 

 fications of the atmosphere. As we have already remarked, 

 the oldest strata contain only marine plants exhibiting cel- 

 lular tissue, the devonian strata being the first in which some 

 cryptogamic forms of vascular plants are found (calamites 

 and lycopodiacese ( 31 ?). It had been inferred from certain 

 theoretical views concerning the simplicity of the primitive 

 forms of organic life, that in the ancient world, vegetable 

 had preceded animal life, and that the former was in fact 

 always the indispensable condition of the latter. But there 

 do not appear to be any facts to justify this hypothesis ; and 

 the circumstance that the Esquimaux, and other tribes who 



