once he declared the bones to be those of an elephant. It was not the kind of 

 elephant, from Africa or from India, that one sees at a menagerie, but a kind of 

 elephant nevertheless. But there are no elephants in the region of Paris! 

 That is true, Cuvier admitted; but at one time there must have been. And 

 none of their descendants are living today. Cuvier beheved that the earth had 

 several times been cleared of its living inhabitants, and repopulated by a new 

 set especially created — that the elephants of today resemble certain elephant- 

 like animals of the past, but that they are in no way related. Others find it 

 easier to imagine that the life of today has descended from the life of the past. 



How Can Different Species Be Related? 



Resemblances and Relationships The historical idea of plant and animal 

 species is that the members of a species are all descended from the same an- 

 cestors. But in describing a species we have assumed relationship, or common 





^i' 



Carnegie Institution of Washington 



BONES FROM THE CALIFORNIA TAR PIT 



Among the bones removed from the tar pit at La Brea were many belonging to animals 

 that are not known to be living anywhere today — saber-toothed tigers, mastodons, 

 species of camels, extinct horses and various birds and small mammals 



455 



