GENERAL LAWS OF DISTRIBUTION. 187 



gether 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 

 found on both their shores are the same. 



398. There is an evident relation between the fauna of 

 any locality and its temperature, although, as we shall here- 

 after see, similar climates are not always inhabited by similar 

 animals, (401, 402.) Hence the faunas of the two hemis- 

 pheres 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 tropi- 

 cal floras. Hence, also, animals 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 depend 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 limi- 

 tation 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 flower- 

 ing plants. 



