HISTORY OF ZOOLOGY. 2/ 



Evolution vs. Creation. Lamarck's spirited writings 

 remained almost unnoticed by his contemporaries. On the 

 other hand there arose a violent controversy between the 

 defenders and the opponents of the Evolution theory 

 when in 1830 Geoff roy St. Hilaire in the Academy at Paris 

 defended against Cuvier in a debate the thesis of a near 

 relationship of the vertebrates and the insects, and set up 

 the proposition that the latter were "vertebrates running 

 on their backs." The conflict ended in the complete over- 

 throw of the Descent Theory ; the defeat was so complete 

 that the problem vanished for a long time from scientific 

 discussion, and the theory of the constancy of species 

 again became dominant. This error was occasioned by 

 many causes. Above all, the theory of Geoffroy St. 

 Hilaire and Lamarck was rather a clever conception than 

 founded on a rich empiric material; besides, it had in it 

 as a fundamental error the doctrine of the serial arrange- 

 ment of the animal world. Opposed to this stood Cuvier's 

 great authority and his extensive knowledge, which latter 

 made it easy for him to show that the animal kingdom was 

 made up of separate co-ordinated groups, the types. 



Lyell. In the same year in which Cuvier obtained his 

 victory, for a long time decisive, over Geoffroy St. Hilaire, 

 his theory of the succession of numerous animal worlds 

 upon the globe received its first destructive blow. Cuvier's 

 cataclysm theory had its two sides, a geological and a 

 botanico-zoological. Cuvier denied the continuity of the 

 various terrestrial periods, as well as the continuity of 

 the fauna and flora belonging to them. In 1830-32 

 appeared the "Principles of Geology' by Lyell, an 

 epoch-making work, which in the realm of geology com- 

 pletely set aside the cataclysm theory. Lyell proved 

 that the supposition of violent revolutions on the earth 

 was not necessary in order to explain the changes of 

 the earth's surface and the superposition of its strata; 

 that rather the constantly acting forces, the liftings and 

 sinkings, the erosive action of water, be it as ebb and flow 

 of the tide, as rain, snow, or ice, or as the flow of rivers 



