88 Trans. Acad. Sci. of St. Louis. 



forms Lamarck rejected the cataclysm theory of Cuvier by 

 which the latter accounted for the successive series of animals 

 and plants found in the fossiliferous rocks of each geological 

 age. According to the doctrine of cataclysms a great revo- 

 lution or convulsion of nature had brought to an end each 

 period of the earth's history, with the destruction of all 

 life, and upon the newly formed earth a fresh and newly 

 created world of fixed species had been placed by the Creator, 

 only to be wiped out of existence in its turn by the next cat- 

 aclysm. Lamarck's spirited writings remained almost un- 

 noticed by his contemporaries, and met with only contempt 

 from Cuvier who spoke of each edition of his works as a 

 ** nouvelle folie.'' 



In 1830, a year after Lamarck's death, Cuvier won his 

 famous victory over St. Hilaire, with the result as already 

 mentioned, that the doctrine of the mutability of species re- 

 mained buried until it was revived nearly thirty years later by 

 Darwin and Wallace. In the same year, however, Cuvier' s 

 theory of cataclysms received its death blow from the geolo- 

 gist Lyell who in his epoch-making work, the ** Principles of 

 Geology," completely set aside the doctrine of convulsions 

 and explained the past changes of the earth's surface as due, 

 not to violent intermittent revolutions, but to the constant 

 action of physical agents which are still in operation, as for 

 example, the erosive action of water. Only gradually then 

 has one period of the earth's history passed into the next and 

 without any break in the continuity. For these changes 

 to have taken place vast periods of time must have been 

 necessary; and it is with this deduction from LyeU's work 

 that the biologist is especially concerned, as it allows of the 

 requisite length of time for the changes to have taken place 

 in the organic world in the gradual evolution of species. And 

 from this point of view Lyell furnished Darwin with a strong 

 support for his theory. 



Darwin . — So complete had been the overthrow of the 

 transmutation-theory that the special- creation view of species 

 rested quietly for over a quarter of a century without receiv- 

 ing a serious attack. Evolutionary doctrine had remained 

 obscured for so long that Darwin's ** Origin of Species" 



