784 GEOLOGY 



perhaps even -greater than has been indicated. It has been con- 

 jectured that North America was connected with Asia on the west , 

 via Alaska, and with Europe on the east, via Greenland and Ice- 

 land. Land seems to have failed of making a circuit in the high 

 latitudes of the north only by the strait or sound east of the Urals. 

 In the southern hemisphere, it has been surmised that Antarctica 

 was greatly extended, connecting with South America, Australia, 

 and possibly with Africa, and that Africa and South America were 

 connected across the Pacific 1 from some earlier time until after 

 the beginning of the Eocene. The basis for these conjectures N 

 found in the distribution of life at that time, as shown by fossils. 



If these conjectured extensions of land were real, it will be seen 

 that the division of land and water in the northern and southern 

 hemispheres was far less unequal than now, and that the land was 

 massed in high latitudes to a greater extent than at present, while 

 tropical seas were more extensive. If extensive polar lands were 

 the cause of glacial periods, as has been suggested, the geographic 

 conditions of the Eocene were favorable in the extreme, if the 

 relations sketched above were the real ones. In spite of this, the 

 climate of the period seems to have been genial, and less markedly 

 zonal than now. 



Close of the Eocene. During the later part of this period, and at 

 its close, there were some notable deformations in Southern Europe. 

 The initiation of the Pyrenees, and of some of the mountains farther 

 east, is assigned to this time, and the distribution of the later forma- 

 tions, when compared with the distribution of the Eocene, shows 

 that changes of a less pronounced type were in progress. The 

 greater deformations which express themselves in the mountain* 

 of Southern Europe are post-Eocene, and most of them con*ider- 

 ably later than the close of the Eocene. 



THE EOCENE LIFE 

 The Transition from the Mesozoic 



Four salient features marked the transition of life from the 

 Mesozoic to the Cenozoic: (1) Among marine animals, nearly all 

 1 Neumayr, Erdegeschichte, Bd. II. 



