PALEONTOLOGY ' 335 



iritornal forces may have been can onlj' he conjectured, but some possi- 

 bilities are pointed out in the following chapter. If the evolution of fins 

 and tails and plates and horns and ponderous size was due to internal 

 causes, these" causes may have effected still further evolution, until 

 animals were produced that were unable to cope with the environment, 

 whether that environment changed or not. Undoubtedly the environ- 

 ment did change during late Cretaceous time, as it is always changing; 

 but there is nothing to indicate that this environmental change was 

 responsible for the extinction of the dinosaurs. 



Some one has wittily expressed the view that the extinction of groups 

 was occasioned by factors within the animals by saying that they "died 

 of evolution." 



It may be pointed out that nations of men have also risen to prominence 

 in the world, have been leaders for a period, and then sunk into oblivion, 

 to be succeeded by other nations. However, the origin and extinction 

 of animal races and the rise and fall of nations may have nothing in 

 common, except the fact that no one knows the cause of either 

 phenomenon. 



Prehistoric Man. — The difficulty in an attempt to relate the rise and 

 fall of nations of men to the evolutionarj'' cycles of other animals is that 

 nations are usually not biological units. They are political units, often 

 held together by common language or by force, and with few exceptions 

 do not represent racial unity. Abandoning, however, the artificial 

 classification of men into peoples, and regarding the human race as a 

 unit, we may find in man the same progressive development as in any of 

 the other great groups of animals which once held a dominant place in the 

 world. Man has had his rise, as did the reptiles, and before them the 

 Amphibia and fishes. Whether he is also to experience a decline and 

 extinction remains for the future to reveal. 



Structurally man plainly belongs to the Primates, an order of mam- 

 mals including the monkeys, marmosets, baboons, gorillas, and the like. 

 To some of these animals he bears much more resemblance than to others. 

 Thus, there is no question that the anthropoid apes stand much nearer to 

 man, structurally, than do the other primates. Were one to look for 

 evidences of genetic relationship of man to the other mammals, structure 

 would point to these apes as furnishing the nearest living connection. 



Actual establishment of this connection through fossil remains has 

 been long delayed. Even now it rests on a series of fragmentary remains 

 which, when compared with the reptilian, cephalopod, or mammoth 

 record, appears meager. However, taken in connection with the ana- 

 tomical evidence, there is scarcely room to question the common ancestry 

 of man and the apes. 



The oldest remains that indicate an approach toward human charac- 

 teristics were found on the island of Java in 1894. They consisted of 



