254 



FIRST YEAR SCIENCE 



117. Distribution of Animals. An examination of a globe 

 shows (1) that the land is massed around the north pole, 

 (2) that the three continental masses to the south are 

 separated from each other by wide seas, and (3) that 

 while two of these are connected by narrow strips of 

 land to northern continents, the third is entirely sepa- 

 rated from all other land: 



But slight changes in elevation would connect the 

 northern continents with each other. As they are so 

 closely related to each other, it might be expected that 

 the animals of these continents would resemble each other, 



particularly in the more 

 northern parts. This 

 is true. Bears, wolves, 

 foxes, elk, deer and 

 sheep of nearly related 

 species are found dis- 

 tributed over the north- 

 ern continents. 



The animals of the 

 southern continents are 

 much less nearly re- 

 lated. The ostrich, 

 giraffe, zebra and hip- 

 popotamus are among 



OSTRICHES. 

 The largest of all birds. 



the characteristic animals of Africa which are not found 

 elsewhere. In South. America the tapir, great ant eater, 

 armadillo and llama are among the animals not represented 

 elsewhere. Both of these continents, however, have ani- 

 mals closely related to those of other great divisions, 

 showing that their present isolation has not continued far 

 back in geological time. 



The animals of Australia differ greatly from those of 

 the other continents. The quadrupeds here are 



