1 8 INTRODUCTION 



animal origin ; but the publication of Cuvier's " Memoir 

 on Fossil Elephants," in 1800, was the beginning of 

 those profound researches on the remains of ancient 

 life which created Paleontology. The discovery of the 

 true relation between all animals, living and extinct, 

 opened a boundless field of inquiry ; and from that day 

 the advance of Zoology has been unparalleled. Special 

 studies of particular parts or classes of animals have so 

 rapidly developed, that the history of Zoology during 

 the last fifty years is the history of many sciences. 3 



But to Charles Darwin more than to any other inves- 

 tigator is due the credit for the great mass of researches 

 which has been accumulated during the last half cen- 

 tury. The publication of the " Origin of Species," in 

 1859, marks the starting-point of modern zoological re- 

 search. Darwin's statement of the facts of evolution 

 and his theory of the causes which produce species of 

 organisms, both plant and animal, attracted the atten- 

 tion of all biologists, and now practically all investiga- 

 tion in the sciences of zoology and botany is carried on 

 in the light of the great principle of evolution. 



