THE ANCESTORS OF THE BIG TREES. 471 



closing Bering Straits and the English Channel, enabled them to spread 

 all over the northern hemisphere and even into the southern, for in the 

 next age, the Eocene, we find their remains in far-off Australia and 

 New Zealand,* while others occur in Alaska, stragglers from the migra- 

 tion into Asia. 



The great frozen north of to-day had not yet been hinted at, a 

 warm, if not subtropical, climate prevailed even in the far north, and 

 Greenland was the garden spot that its name implies. On its western 

 coast many plant-beds have been discovered, containing the remains 

 of tree-ferns, cycads, incense cedars, figs, camphor trees, magnolias, 

 eucalypts and other natives of warm climes. This northern region 

 with numerous land connections to lower latitudes was probably the 

 original home of our modern floras and faunas, which spread south- 

 ward in successive waves of migration. We know that the Mid-Creta- 

 ceous witnessed the apparently sudden appearance of a host of new 

 and higher plant types, and the basal Eocene witnessed, a like sudden 

 appearance of mammalian types. It is to the frozen north of to-day 

 that we look, hopeful that it will shed light on ancestral forms that 

 flourished there in the far distant past. 



With the ushering in of the Eocene period the gigantic reptiles are 

 entirely replaced by higher types ; small mammals, some races of which 

 soon attained great size, uncouth beasts long since passed away, besides 

 the remote and generalized ancestors of some of our modern animals. 

 It is in the rocks of this period that we find the dainty little four-toed 

 ancestor of the horse. The Eocene, together with the next period, the 

 Oligocene, represents a couple of million years, during which the 

 sequoias were almost as abundant and widespread as are the pines in 

 our existing flora. In Fig. 4 are shown some of the characteristic 

 animals of these periods, and in Fig. 1 we get some idea of the geolog- 

 ical and floral conditions. In the far west this was a time of plains, 

 rivers and lakes, the verdant surroundings of the latter rivaling the 

 Louisiana country of the present day. 



Along with the sequoias were many hardwood trees — oaks and 

 maples, hickory and ash; alligators pushed their way through the 

 sedges; the cypress and palmetto grew in Montana, Colorado and 

 Greenland. Stately palms furnished shade for primitive rhinoceroses, 

 tapirs and camels. Monkeys swung from branch to branch and gath- 

 ered the fruits, where to-day there is nothing but the barren wastes of 

 the alkali ' bad-lands.' 



The next period, the Miocene, witnessed the zenith of sequoia devel- 

 opment. Contemporaneous with the tapirs, rhinoceroses, horses and 



* The identification of these antipodean remains is not entirely beyond 

 question. 



