144 ARE SOILS ENRICHED, IMPOVERISHED, pt. hi. 



marvellous variety of species, and of physiological con- 

 stitution, in all the classes named displays itself. The 

 whole of the land and of the water, and even of the air, 

 of these and of all the intermediate regions, are crammed 

 full of organic existences. I will instance only some of 

 the largest quadrupeds, herbivorous and carnivorous, 

 on the extremes of cold and heat, because these could 

 not exist in regions which were not replete with vege- 

 table and animal life for their food. In the arctic 

 regions we find the musk-ox, the reindeer, the huge 

 polar bear, the Avolf, the seal, the whale, &c. ; in the 

 tropics, the elephant, the rhinoceros, the camel, the 

 giraffe, the lion, the hippopotamus, the shark, &c. But 

 Nature is by no means content wdth this wonderful adap- 

 tation of her organic creation to differing physical con- 

 ditions. Like the chicken- fancier, who keeps his fowl- 

 yards separate. Nature seems purposely to have contrived 

 different stations with similar physical conditions, in 

 order to exhibit the profuseness of her creative power 

 in cramming all full of animal and vegetable existences, 

 with constitutions similar to those of similar but sepa- 

 rate stations, but the species of each similar separate 

 station differing entirely from the species of all other 

 similar separate stations. These stations are in general 

 kept separate by what Buffon called ' natural barriers.' 

 Besides the difference of chmate resulting from differ- 

 ence of latitude, difference of altitude and seas of 

 water, or of sand, or of eternal snow, in general sepa- 

 rate terrestrial districts. Continents, currents, difference 



