16 THE MODERN STUDY OF ZOOLOGY 



nearer to the existing forms of animals than do 

 those of the older strata; finally, of the highest 

 forms of animal life man and the quadrumana 

 there are no fossil remains whatever. 



From these conclusions, the importance of which 

 it is impossible to overrate, Cuvier was led to found 

 his doctrine of Catastrophtsm, according to which 

 there have been periodical annihilations at long 

 intervals of time of all the animals living on the 

 earth at the time ; each cataclysm being followed 

 by the creation of a totally new set of animals, 

 which though agreeing in many points with their 

 predecessors, yet presented many marked differences 

 from them. 



Cuvier's doctrines, however, did not meet with 

 general acceptance among geologists, and the pub- 

 lication of the first edition of " The Principles of 

 Geology," by Sir Charles Lyell, in 1830, two years 

 before Cuvier's death, may be said to mark the 

 complete overthrow of the doctrine of catastrophism 

 so far as the changes that have taken place in the 

 earth's crust are concerned. A closer study of 

 what is at present occurring on the earth's surface 

 showed that there are now in action forces amply 

 sufficient, given time enough, to produce changes 

 as great as any of which we have geological record ; 

 that the elevation of great mountain chains is not 

 due to the sudden action of immeasurably great 

 forces but to the long continued action of appar- 

 ently insignificant ones ; and that there is not only 

 no evidence whatever of the occurrence of the 

 supposed catastrophic periods, but that all the 



