"As concerns 'Relations Physiology', i.e., the study of 

 the relations of the animal organism to the external 

 world, this in turn falls into two segments, ecology and 

 chorology. By ecology we mean the body of knowledge 

 concerning the economy of nature— the investigation of 

 the total relations of the animal both to its inorganic and 

 to its organic environment; including, above all, its 

 friendly and inimical relations with those animals and 

 plants with which it comes directly or indirectly into 

 contact— in a word, ecology is the study of all those com- 

 plex interrelations referred to by Darwin as the condi- 

 tions of the struggle for existence. This science of ecology, 

 often inaccurately referred to as 'biology' in a narrow 

 sense, has thus far formed the principal component of 

 what is commonly referred to as ''Natural History. As is 

 well shown by the numerous popular natural histories of 

 both early and modern times, this subject has developed 

 in the most close relations with systematic zoology. The 

 ecology of animals has been dealt with quite uncritically 

 in natural history; but natural history has in any case had 

 the merit of keeping alive a widespread interest in 

 zoology." 



Ernst Haeckel, 1870 



