414 GENERAL ZOOLOGY. 



III. MESO zoic AGE. 



Divided into (1) Triassic, (2) Jurassic, and (3) Cretaceous 

 periods. This was the age of reptiles, the group reaching 

 its culmination in the Cretaceous, some of the species being 

 of gigantic size. The mammals appear in the Triassic, 

 but they are few in number and are rare in the other 

 Mesozoic rocks. The earliest known birds are in the 

 Jurassic. 



IV. C^NOZOIC AGE. 



Divided into (1) Eocene, (2) Miocene, (3) Pliocene, (4) 

 Pleistocene, and (5) Recent periods. The first three periods 

 are grouped as the Tertiary the other two as the Quaternary 

 divisions. The Caenozoic is pre-eminently the age of 

 mammals. 



EVOLUTION. 



It was long thought that the million or more different 

 species of animals on the earth (and the same is true of 

 plants) were specially created and placed in conditions 

 best adapted for them, but with deeper knowledge this 

 view has now become obsolete. At the beginning of the 

 last century (1809) Lamarck advanced the view that the 

 living species had come into being by modification of 

 pre-existing forms. The time was not ready for this 

 view; the facts had not been accumulated to support it 

 and so it was forgotten, until, in 1859, Darwin published 

 his "Origin of Species," which put the theory of evolution 

 upon a firm basis, and which since that time has influenced 

 almost every line of human thought, and has been accepted 

 by every zoologist, in its broader features, although there 



