CHARLES ROBERT DARWIN. 375 



ural to conclude that the living have descended 

 from the fossils. 



The study of the rocks has produced other " miss- 

 ing links " in the succession of animal life. Pro- 

 fessor Huxley, in some lectures given in New York 

 in 1876, described the Hesperornis, found in the 

 western rocks, a huge bird, five or six feet in 

 length, with teeth like a reptile. In England a 

 fossil reptile has been found, the Archaeopteryx, 

 having a reptile-like tail, with a fringe of feathers 

 on each side, and teeth, "occupying a midway 

 place between a bird and a reptile." Flying rep- 

 tiles have been found, and reptiles which walked 

 on their hind legs. Those who have visited Yale 

 and Amherst Colleges must have seen the huge 

 bird-tracks or reptile foot-prints taken from the 

 rocks in the Connecticut valley. 



Professor Huxley showed the probable descent 

 of the horse with its hoofed foot from the extinct 

 three-toed Hipparion of Europe, and that from the 

 four-toed Orohippus of the Eocene formation. He 

 declared it probable that a- five-toed horse would 

 be found, and Professor Marsh, in the West, has 

 found the Eohippus, corresponding very nearly to 

 Professor Huxley's description. 



The question among naturalists was, "How can 

 plants and animals have become thus changed ? " 

 Darwin showed how it was possible to effect most 

 of these changes by "natural selection," or the 

 choosing of the best to survive in the struggle for 

 existence. As man by grafting secures the finest 



