CHAPTER X 



GENERAL BIOLOGY 



About the beginning of the nineteenth century many dis- 

 tinguished men of science seem independently to have developed 

 the idea that the structure of animals and their occurrence in 

 various localities are determined by external conditions. 



Lamarck in his Philosophie zoologiqtte (1809) writes as 

 follows : " The external conditions always and strongly exert 

 their influence on all living beings. This influence is, however, 

 difficult to ascertain, because its effects only appear, and may 

 be recognised, after a very long time." 



Goethe's zoological works all testify to his strong belief 

 that "all living beings possess the faculty of adapting them- 

 selves to the manifold conditions presented by external 

 influences, without, however, resigning a certain hard-earned 

 and decided independence." In his Skeletons of Rodents he 

 says that " the difference of forms is a consequence of their 

 necessary dependence on the outer world." In his introduction to 

 comparative anatomy he attempts to show the various influences 

 exerted by certain climatic conditions, by water, and by air upon 

 the shape of animals, which become altered on passing from one 

 group of conditions to another. This again explains the fact 

 that " no organism intended to live is conceivable without a 

 perfect organisation." Goethe was full of such ideas, but felt 

 the danger of following them up, and of "losing oneself in the 

 infinite " {^Principles of Zoological PJiilosophy\ 



Kant's view is still clearer as regards the idea of adaptations 

 to surroundings. He endeavoured to show that all biological 

 investigations had to take for granted that living beings are 

 fitly organised in relation to their natural surroundings. But 

 no definite human idea of the fitness of adaptations is of any 

 value as knowledge. No more does any human idea necessarily 

 correspond to the reality occurring in nature. The idea is only 



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