476 NINETEENTH CENTURY. FT. HI, 



On the other hand, if instead of going down to lower 

 living forms we go back into the history of the past, 

 Palceontologv, or the study of fossil animals, first brought 

 into prominence by Cuvier in 1812, teaches the same 

 lesson. We saw (p. 435) how the discovery of animals 

 slightly differing from living ones startled the world at the 

 beginning of the century, and since then, year after year 

 has been adding to the evidence (p. 462) that life in the 

 past helps us to complete the links between different living 

 forms. Of late the chief additions to our knowledge have 

 been made in America, where Dr. Leidy, Professor Cope, 

 and Professor Marsh have brought to light an immense 

 number of fossil skeletons. Some of these help us to trace 

 the gradual development of animals, as in the case of the 

 horse, whose probable ancestors have now been found 

 among the fossils of the Rocky Mountains, beginning with 

 a little creature about the size of a fox, with real toes 

 instead of a hoof; showing that, whereas the horse was 

 formerly believed to have been always confined to Europe, 

 till it was taken to America by the Spaniards, in real truth 

 its ancestors were American, and it must have migrated to 

 Europe in past ages. Others, again, are curious animals, 

 half reptiles, half birds, and some of these are so enormous 

 that it is difficult to imagine how they can have walked as 

 they did on their hind feet. The largest of these mon- 

 sters, Titanosaurus montanus, found by Professor Marsh 

 in Colorado, must have measured from fifty to sixty feet in 

 length, and have been at least thirty feet high when it stood 

 upright. It lived in the Cretaceous period, or about the 

 time when all the chalk of our North and South Downs 

 was being formed in the depth of the sea. 



It is easy to see that such discoveries as these make us 

 take a much grander view of the history of animals and 



