HISTORY OF ZOOLOGY 17 



of a near relationship of the vertebrates and the insects. The conflict 

 ended in the complete overthrow of the theory of evohition; the defeat 

 was so complete that the problem vanished for a long time, and the 

 theory of the fixity of species again became dominant. This was occa- 

 sioned by many causes. The theorj^ of Gcoffroy St. Hilaire and Lamarck 

 was rather a clever conception than founded on abundant facts; besides, 

 it had in it as a fundamental error the doctrine of the serial arrangement 

 of the animal world. Opposed to this stood Cuvier's extensive knowledge, 

 making 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, his 

 theory of the succession of numerous animal worlds upon the globe 

 received its first blow. Cuvier's cataclysm theory had two sides, a geo- 

 logical and a biological. Cuvier denied the continuity of the various 

 terrestial periods, as well as the continuity of the fauna and flora belonging 

 to them. In 1S30-32 appeared the "Principles of Geology" by Lyell, 

 which, in the realm of geology, completely set aside the cataclj'sm theory. 

 Lyell proved that the supposition of violent revolutions was not necessary 

 to explain the changes of the earth's surface and the superposition of its 

 strata; that rather the constantly acting forces, elevations and depressions, 

 the erosive action of water, are sufficient to furnish a complete explanation. 

 Verj' gradually in the course of time the earth's surface has changed, and 

 passed from one period into the next, and still at the present day constant 

 change is going on. The continuity in the history of the earth, here 

 postulated for the first time, has since then become one of the fundamental 

 axioms of Geology; on the other hand the discontinuity of living creatures, 

 was for a long time regarded as correct. 



Darwin. — It is the great merit of Charles Darwin that he took up the 

 theory of descent anew after it had rested a decade, and later brought it 

 into general recognition. With this began the most important period in 

 the history of zoology, a period in which the science not only made such 

 an advance as never before, but also began to obtain a permanent influ- 

 ence upon the general views of men. 



Charles Darwin was born in i8og. After studying at the universities 

 of Edinburgh and Cambridge, he joined the English war-ship "Beagle," 

 as naturalist. In its voyage from 183 1 to 36 around the globe, Darwin 

 recognized the peculiar character of island faunas, particularly of the 

 Galapagos Islands, and the remarkable geological succession of edentates 

 in South America; these facts formed the germ of his epoch-making 

 theory. After his return to England Darwin lived, entirely devoted to 

 scientific work, up to his death in 1S82. He was incessantly busy in 



