THE VALUE OF ECOLOGICAL SURVEYS 29 



species or group of organisms, if its place in the econ- 

 omy of nature is understood. A vast number of the 

 problems of the economic zoologist are thus problems, 

 not so much of individual or aggregate ecology, but 

 ones in which the balance of the whole local biotic 

 association is concerned. 



This was the fact pointed out by Mobius when he 

 studied the oyster and came to see that it must be 

 studied not in isolation but as a member of a com- 

 munity, association of animals, or a biocoenosis, 

 as he called these interrelated organisms. These 

 facts are mentioned, as examples from a vast number 

 that are recorded, to show that our applied or 

 economic zoology and entomology are fundamentally 

 more closely related to associational ecology than to 

 any other phase of zoology, and to suggest that it 

 would be to the great advantage of the students 

 of such problems if they clearly understood this 

 relation. This is also an argument for the ecological 

 organization of a vast number of natural history 

 surveys, because the associational grouping of 

 observations and responses gives the most intimate 

 knowledge of the life of animals in the network of 

 their environmental relations. 



In addition to the balance of nature which is 

 found within the small associational units there are 

 the larger ones of considerable geographic extent, 

 which the students of faunal or floral problems fre- 

 quently call zones or distinct regions. Some of these 

 are distinct ecological units, whose dynamic status 

 should be determined, so that we may know and 



