TIk- word t-coloi/y. (lerivetl from tin- (iri'ek 

 words oik'os moaning liahitation, and loijos meaning 

 discourse or study, implies a study of tlie habitations 

 of organisms. 



luology was first described as a sejwrate field of 

 knowledge in 1866 by the German zoologist Krnst 

 Haeckel, who invented the word oekoloijic for "the 

 relation of the animal to its organic as well as its in- 

 organic environment, particularly its friendly or hos- 

 tile relations to those animals or plants with which it 

 comes in contact." 



Ecology has been variously defined by other in- 

 vestigators, as "scientific natural history," "the study 

 of biotic communities," or "the science of community 

 populations" ; probably the most comprehensive defi- 

 nition is the simple one most often given : a study oj 

 animals and /slants in their relations to each other 

 and to their environment. 



OBJECTIVE.S 



Ecology is a distinct science because it is a 

 body of knowledge not similarly organized in any 

 other division of biology : because it uses a special set 

 of techniques and procedures ; and because it has a 

 unique point-of-view. The essence of this science is a 

 comprehensive understanding of the import of these 

 phenomena : 



1. The local and geographic distribution of 

 organisms : 



2. Regional variations in the abundance of or- 

 ganisms ; 



3. Temporal changes in the occurrence, abun- 

 dance, and activities or organisms ; 



4. The interrelations between organisms in popu- 

 lations and communities : 



5. The structural adaptations and functional 

 BctchsrOimd: adjustments of organisms to their physical 



environment : 



6. The behavior of organisms under natural con- 



The Scope and 7. The evolutionary development of all these in- 



terrelations : and 

 History of EcoloSy S. The biological productivity of nature and how 



this may best serve mankind. 



METHODS 



To the achievement of these objectives tlie 

 following methods or points of attack are funda- 

 mental : 



Observation in detail of how organisms live un- 

 der natural conditions. 



1 



