362 NATURAL HISTOEY. 



are of a dull color. Not a bird of bright plumage is to 

 be found. Of terrestrial animals, the most noticeable are 

 the White Bear, the Reindeer, the White Fox, etc. ; and 

 of the aquatic Mammals, the Seals and the Whales. There 

 are no reptiles, few insects, and no coral animals. 



630. In the Faunas of the temperate regions there is 

 much greater variety than in those of the arctic. Ter- 

 restrial animals abound here. The birds exhibit consid- 

 erable variety of color. One of the prominent features 

 of the Fauna of the temperate zone is the constant change 

 which is going on in it from the variety in the seasons. 

 Especially is this true of the northern portion. In the 

 colder months insect life has retired for hibernation, and 

 vegetable life is, for the most part, in a similar state. 

 The sources of livelihood for many animals are thus cut 

 off. The birds, therefore, migrate to warmer regions, 

 and many of the mammals hibernate ; and in the spring 

 the mammals wake up, and the birds return, making na- 

 ture, which was so still in winter, vocal again. 



631. Abundance, variety in form, and brilliancy of col- 

 ors are the distinguishing characteristics of the tropical 

 Faunas. " All the principal types of animals," say Agas- 

 siz and Gould, -" are represented, and all contain numer- 

 ous genera and species. We need only to refer to the 

 tribe of Humming-birds, which numbers not less than 300 

 species. It is very important to notice that here are con- 

 centrated the most perfect, as well as the oldest types of 

 all the classes of the animal kingdom. The tropical re- 

 gion is the only one occupied by the Quadrumana, the 

 herbivorous Bats, the great Pachydermata, such as the 

 Elephant, the Hippopotamus, and the Tapir, and the whole 

 family of Edentata. Here, also, are found the largest of 

 the Cat tribe, the Lion and Tiger. Among the Birds, we 

 may mention the Parrots and Toucans as essentially trop- 

 ical ; among the Reptiles, the largest Crocodiles and gi- 

 gantic Tortoises ; and, finally, among the articulated an- 

 imals, an immense variety of the most beautiful insects. 



