TERTIAEY PERIOD BY MEA.NS OF THE MAMMALIA. 403 



Animals extinct : — AT) 



Brown bear : circa 500-1000. 



Eeindeer „ 1200. 



Beaver , 1100-1200. 



Wolf „ 1680. 



Wild boar „ 1620. 



Animals introduced : — 



Domestic Fowl before 55 B.C. 



FaHow deer circa 50-100 A.D. 



Pheasant „ 50-100 A.D. 



Domestic ox of Urus type ,, 449 A.D. 



Ass „ 800-850 A.D. 



Cat „ 800-lOOOA.D. 



Common rat „ 1727-1730 A.D. 



25. The Prehistoric and Historic Periods helong to the Tertiary. 



If the list of Prehistoric Mammalia be compared with that of the 

 late Pleistocene, it will be seen that great differences are to be 

 observed. jS'o less than seventeen Pleistocene species have dis- 

 appeared from Britain in the interval separating the one from the 

 other, some having become extinct, others j having retreated to the 

 north or to the south, or to the shelter offered by the forests of 

 Central Europe, or to the cold climate of lofty mountains. It must, 

 however, be remembered that all the wild Prehistoric animals were 

 living in the preceding age, and that from the Pleistocene age 

 down to the present time the wild fauna and jlora of Europe have 

 been what they are now. The continuity has been unbroken. 

 It is therefore evident that the Tertiarj^ period must bo extended 

 so as to include the events of our own times. 



26. General Conclusiotis. 



From this imperfect outline of the groups of Placental mammals 

 living in Europe in successive times, it is obvious that they present 

 us with a means of classifying the Tertiary period with greater 

 detail and certainty than those of the lower animals. The groups 

 chosen as typical are those which seem to me to be the most im- 

 portant; but it must be noted that their apparent isolation is 

 merely the measure of the imperfection of our knowledge and of 

 the geological record. They show that in the Tertiary period the 

 Placental mammals were gradually becoming more specialized and 

 more like living forms. "When living forms appear, man appears 

 also in the Pleistocene age. A reference to the table in which 

 these changes are represented (p. 381) will at once show that it is 

 hopeless to look for Eocene or Miocene man, and that his existence 

 in the Pliocene is most improbable. The relation of the groups to 

 one another proves further that each phase of tlie Tertiary is in- 

 timately connected with that which went before and that which 

 followed after, and that the Tertiary period embraces all the events 

 which happened from the close of the Secondary to the present day. 



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