THE KEVOLUTIONS OF THE CRUST OF THE EARTH. 321 



Among all the fossil mammals none more excite the interest of scien- 

 tific men and the curiosity of the public than the mammoth. Its great 

 height of from twelve to fifteen feet, the size of its tusks, its trunk, give 

 it a sort of family likeness to the elephant ; however, its thick reddish 

 hair, the remains of pine branches found in its stomach, the discovery 

 of a mammoth, preserved entire in the ice of Siberia, denote that it was 

 not an inhabitant of the tropics like its congener, the elephant, but of 

 the temperate and cold zones of Central Asia and of America. 



A species nearly allied to the preceding, the mastodon, formed in its 

 cosmopolitism an exception to the continental localization not only of 

 the living animals, but also of the fossil mammals of the Pliocene and 

 Post-Pliocene formations. The mastodon is represented by species differ- 

 ing very little in Asia, in the two Americas, and even in Australia ; 

 and what is worthy of remark, it is the only quadruped that lived upon 

 the latter continent which was at the same time represented by analo- 

 gous species in some other part of the world.* 



The ruminants occupy the second place in the succession of the herbi- 

 vores. Magnificent stags with enormous horns, fallow-deer, elks, 

 gazelles, reindeer, and other known species, browsed together upon the 

 same vast plains, while to-day these species are distributed over every 

 zone and throughout all parts of the world. These inoffensive crea- 

 tures, which with other Herbivores occupied almost exclusively the sur- 

 face of the globe, were soon obliged to defend themselves from the 

 attacks of the carnivorous animals, which lay in wait for them in the 

 forests, and i)ursued them in the open plains. In proportion as we 

 approach the upper strata of the sedimentary crust, the number of the 

 Carnivores increases rapidly; for beside the large dogs, nearly five feet 

 high, which were i)robably the first to appear, we find representatives 

 of the cat family, of the plantigrades, and of the wolves. The bone- 

 caves, excavated for the most part by the action of the sea, are filled 

 with the remains of the bones of a great number of animals, and, as has 

 been stated, in some cases, with the imprint of the teeth of Carnivores 

 upon them, it is thought of the animals which carried these bones into 

 the caves. 



If we attentively examine the development of organized beings, and 

 compare it with the strati grai)hic development of the earth's crust, we 

 find that there is a certain parallelism which can be traced throughout 

 all the geological periods. When the crust of the globe was only a 

 thick sediment without apparent stratification, resting upon the cooled 

 lava, what living creatures inhabited the earth ? Some Infusoria hardly 

 more complicated in structure than snow crystals or other mineral con- 

 cretions, whose individuality was constituted as much of silica as of 

 carbon. In our time we would say almost that the richness of strata is 

 in proportion to the richness of animal life. Asia, extremely well de- 

 veloped in a stratigraphic and orographic point of view, is also the only 



* Owen, Eeport on the Extinct Mammals of Australia, London, 1845, p. 20. 

 S 21 



