248 GEOLOGY. 



pose, but, in the nature of the case, it could only have been one out 

 of many conceivable purposes. 



Let us now, if we can, form some picture of the character and 

 physical condition of the Tertiary ages. -Take, for example, the 

 middle Pliocene. Had we been in existence then, and started west- 

 ward on a journey from some point near where the Missouri now 

 flows, much of the peculiar life of the times would have been ob- 

 served. The climate was congenial in an eminent degree. The 

 great Pliocene lake caused a much moisture atmosphere than exists 

 at present. Groves of Sequoias, like the present gigantic trees of 

 California, the glyptostrobus of China and Japan, the cypress, the 

 date and the palm, were interpersed with magnificent savannas. 

 The songs of ten thousand birds, many of them of the most beau- 

 tiful plumage, would have greeted our ears. At some places, herds 

 of thousands of Oreodons would have been encountered. Bisons, 

 similar in form to our buffaloes, would have been seen cropping 

 the grass. At other points might have been seen herds of elephants 

 and mastodons quietly proceeding towards some streamlet, or lake- 

 let, to indulge in a bath. Vast numbers of many species of camels 

 would have been seen reposing at mid-day on a gentle hill-side 

 under the shade of sequoias or cypress. More curious than all, 

 thousands of Hyperions, those wonderful three- toed horses, along 

 with many kinds of one-toed horses, of all sizes, would sometimes 

 have made the earth tremble under their tread. When, at last, in 

 such a westward journey, the shores of the great Pliocene lake 

 would be reached, its borders would have been a marvel for the 

 life represented there. A rhinoceros might have been seen wal- 

 lowing in the mud near the shore. Thousands of water-fow 

 would have been riding the gentle waves. Elephants, camels, ore- 

 dons, and horses might have been seen there slaking their thirst in 

 the streamlets flowing into the lake. Life would have been ob- 

 served everywhere — the hum of insects and the song of birds in 

 the air — life in the trees, in forest and glade, on land and lake- 

 Most of it, too, was happy life. It is true some unfortunate rumin- 

 ants would fall victims to the gigantic wolves and cats of the time, 

 but the carnivora were not the rulers of the land. Grass and leaf, 

 and seed, and fruit-eating animals, were the rulers of the Pliocene 

 world in central North America. It was a physical paradise, for 

 violence, rapine, and murder, were the exception and not the rule. 

 Violence, indeed, has existed in every geological age, but in Plio- 



