152 TERRESTRIAL PHENOMENA. 



great inland seas, long inhabited by the same species of ani- 

 mals, have been violently separated, their original connection 

 being still evidenced by the fossil remains of shells and 

 zoophytes. Thus in following phenomena in their mutual 

 dependence, we are conducted from the consideration of 

 forces operating in the interior of our globe, to movements 

 and disruptions of its surface, and to the pouring forth of 

 molten streams forced up by the expansive energy of elastic 

 vapours. The same forces which elevated the lofty chains 

 of the Andes and the Hiinalaya to the regions of perpetual 

 snow, have occasioned new compositions and textures in the 

 mineral masses, and have altered strata which had been 

 previously deposited from fluids containing many organic 

 substances. We thus perceive the dependence of the series 

 of formations, divided and superposed according to their 

 ages, on changes of configuration of the surface, on dynamic 

 relations of the upheaving forces, and on the chemical 

 action of the vapours which issue from the fissures. 



The form and distribution of the dry laud, or of tha,t 

 portion of the earth's crust which is suited to the luxuriant 

 development of vegetable life, are connected by intimate 

 relations, and by reciprocal action, with the surrounding sea, 

 in which organic life seems almost limited to the animal world. 

 The liquid element is again covered by the atmosphere an 

 aerial ocean into which the mountain chains and plateaus of 

 the dry land rise like shoals, and occasion a variety of cur- 

 rents and changes of temperature. Collecting moisture from 

 the region of clouds, these loftier tracts contribute also to 

 the spread of life and motion, by the beneficial influence of 

 the streams of water which flow down their declivities. 



Whilst the geography of plants and animals depends on 



