GENERAL LAWS OF DISTRIBUTION. 155 



of certain types over others, sufficiently prominent to impress 

 upon the group well-marked features. Thus, for example, 

 in the islands of the Pacific are found terrestrial animals, 

 altogether peculiar, and not found on the nearest continents. 

 There are numerous animals in New Holland differing from 

 any found on the continent of Asia, or, indeed, on any other 

 part of the earth. If, however, some species inhabiting both 

 shores of a sea which separates two terrestrial regions, are 

 found to be alike, we are not to conclude that those regions 

 have the same Fauna, any more than that the Flora of Lap- 

 land and England are alike, because some of the sea-weeds 



o ' 



found on both shores are the same. 



398. There is an evident relation between the fauna of 

 any locality and its climate ; and, on that account, the 

 faunas of the two hemispheres have been distributed into 

 three principal divisions, namely, the arctic, the temperate, 

 and the tropical faunas ; in the same manner as we have 

 arctic, temperate, and tropical floras. Hence also, ani- 

 mals dwelling at high elevations upon mountains, where the 

 temperature is much reduced, resemble the animals of 

 colder latitudes, rather than those of the surrounding plains. 



399. In some respects, the peculiarities of the fauna of a 

 region depends upon its flora, at least so far as land animals 

 are concerned ; for herbivorous animals will exist only 

 where there is an adequate supply of vegetable food. But 

 taking the terrestrial and aquatic animals together, the distri- 

 bution of a fauna is less intimately dependent on climate 

 than that of a flora. Plants, in truth, are for the most part 

 terrestrial (marine plants being relatively very few), while 

 animals are chiefly aquatic. The ocean is the true home 

 of the Animal Kingdom ; and while plants, with the excep- 

 tion of the lichens and mosses, become dwarfed or perish 

 under the influence of severe cold, the sea teems with 

 animals of all classes, far beyond the extreme limit of 

 flowering plants. 



