PHILOSOPHIC ZOOLOGY 



CHAPTER LXXVIII 



PHILOSOPHIC ZOOLOGY— THE THEORY OF EVOLUTION 

 —EVOLUTION AS A FACT 



Having now considered at some length the relations of animals 

 to their surroundings (or environment), in which, of course, other 

 organisms are included, and having also reviewed the life-cycles 

 or life-histories of certain typical forms, this work may be fitly 

 concluded by a brief survey of the Theory of Evolution, 

 which at the present day not only dominates the realm of Natural 

 History, but has also had a far-reaching influence upon almost 

 every branch of learning. 



The kinds or species of animal at present existing are almost 

 innumerable, and we know from the geological record that a 

 host of others once lived which are now extinct, some having- 

 become so within the historic period, while others died out 

 millions of years ago. Until the second half of last century it 

 was commonly believed that all these species came into existence 

 by "special creation", and to ask "why?" any kind of animal 

 had a particular structure, developed after a special fashion, 

 exemplified certain habits, or lived in a definite area, was con- 

 sidered undesirable or even impious. The only answer to such 

 questions given by the doctrine of special creation was that these 

 things were so because they had been designed to be so, accord- 

 ing to a plan into which the human mind was forbidden to pry. 

 Now and then, however, from the time of Aristode onwards, 

 this paralyzing dogma failed to satisfy the minds of certain 

 naturalists who were ahead of their times. Among these per- 

 haps the most notable was the eminent French zoologist 

 Lamarck, who in 1801 expressed the view that all existing 



species have descended from, i.e. been evolved from, pre-existing 



477 



