2 ANIMAL ECOLOGY 



prominence that it divides biologists more or less 

 completely into two camps on the one hand those 

 who make it their aim to investigate the actions of the 

 organism and its parts by the accepted methods of 

 physics and chemistry, carrying this investigation as 

 far as the conditions under which each process mani- 

 fests itself will permit ; on the other, those who in- 

 terest themselves rather in considering the place which 

 each organism occupies, and the part which it plays 

 in the economy of nature. It is apparent that the 

 two lines of inquiry, although they equally relate 

 to what the organism does, rather than to what it 

 is, and therefore both have equal right to be included 

 in the one great science of life, or biology, yet lead 

 in directions which are scarcely even parallel. So 

 marked, indeed, is the distinction, that Professor 

 Haeckel some twenty years ago proposed to separate 

 the study of organisms with reference to their place 

 in nature under the designation of 'cecology,' defining 

 it as comprising 'the relations of the animal to its 

 organic as well as to its inorganic environment, 

 particularly its friendly or hostile relations to those 

 animals or plants with which it comes into direct 

 contact.' 1 Whether this term expresses it or not, 

 the distinction is a fundamental one. Whether with 

 the oecologist we regard the organism in relation to 

 the world, or with the physiologist as a wonderful 



1 These he identifies with " those complicated mutual relations which 

 Darwin designates as conditions of the struggle for existence." Along 

 with chorology the distribution of animals cecology constitutes what 

 he calls Relations-physiologic. Haeckel, " Entwickelungsgang u. Auf- 

 gaben der Zoologie," Jenaische Zeitschr., 1869, Vol. V, p. 353. 



