IN MODERN SCIENCE. 



"5 



make their appearance, and at the close of 

 the period forests of broad-leaved trees alto- 

 gether different from those of the Palaeozoic 

 Age, and resembling those of our modern 

 woods, appear for the first time over great 

 portions of the northern hemisphere. 



The Cainozoic, or Tertiary, is the age of 

 mammals and of man. In it the great rep- 

 tilian tyrants of the Mesozoic disappear, and 

 are replaced on land and sea by mammals or 

 beasts of the same orders with those now liv- 

 ing, though differing as to genera and species 

 (see Fig. 5). So greatly, indeed, did mamma- 

 lian life abound in this period that in the mid- 

 dle part of the Tertiary most of the leading 

 groups were represented by more numerous 

 species than at present; while many groups 

 then existing have now no representatives. 

 At the close of this great and wonderful pro- 

 cession of living beings comes man himself — 

 the last and crowning triumph of creation ; the 

 head, thus far, of life on the earth. 



I have merely glanced at the leading events 

 of this wonderful history, because its details 

 may be found in so many manuals and popular 

 works on geology. But if we imagine this 

 great chain of life extending over periods of 



