GEOLOGICAL SUCCESSION. 7 



it the only backboned animals were fishes, amphibians (repre- 

 sented at the present time by newts, frogs, &c.), and, towards 

 the end, some reptiles^ In the next great period, the Secondary 

 or Mesozoic, the reptiles were of the greatest importance : they 

 were very numerous and some were of gigantic size. They 

 became fitted for various modes of life, some inhabiting the 

 land, others the sea ; some living on a vegetable diet, others 

 on flesh. During this period also the birds began to come into 

 existence, and remains of the most remarkable of the early 

 forms of birds, Archaeopteryx, are shown in table-case 13. At 

 the same time the first of the warm-blooded mammals arose, 

 though they were as yet insignificant in size and numbers. 

 The third period, the Caenozoic, is that with which we are 

 chiefly concerned. During it the reptiles became of little 

 importance, while, on the other hand, the mammals took 

 their place, becoming extremely numerous, many of them 

 of great size, and adapted to every kind of life and food. The 

 latter part of this period, sometimes called the Quaternary, 

 extends till the present day, and during it the mammals 

 still continue to be the prominent backboned animals, but 

 one of them, man, has become by far the most important 

 inhabitant of the world, and instead of merely being slowly 

 fitted to new conditions of life, now to a large extent controls 

 the conditions and changes them to suit his own convenience. 



The second table (p. 8) shows what are the chief forms 

 of Proboscideans living at the different periods and their 

 distribution over the world. It will be seen that the earliest 

 mammal which can be definitely called a Proboscidean is 

 Moeritherium, a small tapir-like creature from the Middle 

 Eocene beds of the Fayum district of Egypt. This species 

 existed also in the Upper Eocene of the same region, but 

 was then accompanied by a larger and much more elephant- 

 like animal, Palaomastodon. At this time Africa was cut off 

 from the rest of the world to the north by a broad and deep 

 sea which extended from the Atlantic to the Pacific by way of 

 Northern India and Southern China, and the separation of 

 Africa prevented these early forms of elephant from wandering 

 into other regions till after the Eocene. After Palceomas- 



