270 AN INTRODUCTION TO ZOOLOGY 



with which he was familiar, together with a system of classifica- 

 tion. Thus the way was cleared for the greatest worker in this 

 field, Carl Linnaeus (1707-1778, Fig. 151), who attempted to 

 describe all the existing species of animals and plants. He 

 succeeded in listing 4378 in the tenth edition of his greatest work, 

 Systema Natures. His great influence, and the wide recognition 

 which was accorded his work, made the systematic side of zoology 

 the most active field of investigation for a long time after his 

 death. The aim of the systematic zoologist has been to describe 

 all the species of animals, and to arrange them according to a 

 natural system, i.e. a system that will show their true relation- 

 ships to one another. 



b. Comparative Analomy 



Anatomy up to the sixteenth century consisted in descriptions 

 of the structure of single animals. The points of resemblance of 

 different animals finally led zoologists to compare the anatomy 

 of one with another. The French scientist Cuvier (1769-1832, 

 Fig. 152), may, however, be considered the founder of this branch 

 of zoology, since he extended his studies over the entire animal 

 kingdom, and added a great mass of personal observations to the 

 many descriptions published by his predecessors. Besides a 

 number of treatises on comparative anatomy, he wrote a book on 

 the fossil remains of animals which founded the science of verte- 

 brate paleontology. 



Among Cuvier's more noted successors were the Englishmen, 

 Richard Owen (1804-1892) and Thomas H. Huxley (1825-1895), 

 and the American, E. D. Cope (1840-1897). To Richard Owen 

 we owe the introduction of the ideas of analogy and homology. 

 His work on the comparative anatomy of vertebrates has been of 

 great service ever since its publication. Although Huxley 

 made many investigations and published a number of papers on 

 the comparative anatomy of animals, he is best known because 

 of his influence in popularizing zoology. Cope played an impor- 



