362 © NATURAL HISTORY. 
are of a dull color. Not a bird of bright plumage is to 
be found. Ofterrestrial 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 
eolder 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 yery 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. 
