Article I. — An Outline of the Relations of Animals to their In- 

 land Bnz'iromnents. By Charles C. Adams, Ph.D. 



The Dynamic Relations oe Animals 

 I. introductory note 



As creatures of habit, the attitude of mind with which we approach 

 a scientific problem has much influence upon what we see in it or get 

 from it. Although the essence of life is activity — the response of the 

 changing organism to its changing environment — yet this dynamic 

 conception of animal relations, and all that it implies, has not become 

 as prevalent a mental habit among biologists as one might expect. 

 While some naturalists view the animal from a more or less dynamic 

 standpoint, they do not include a similar conception of the relation of 

 an animal to its environment. Still others view the environment more 

 or less dynamically but do not extend this conception to the animal, 

 and thus both of these conceptions lack completeness and are not thor- 

 oughgoing and consistent. The study of activities, or in other words 

 the study of processes, has made great progress in the allied sciences, 

 much to their advantage, and undoubtedly the prevalence of similar 

 conceptions will lead to similar advances in biology. 



In the present brief paper I have attempted to discuss only certain 

 phases of the problem with the idea of emphasizing the general prin- 

 ciples involved, and in the hope that it may aid in making these con- 

 ceptions of more practical value in investigation, and also facilitate an 

 understanding of the discussion contained in a report on the inver- 

 tebrates of the Charleston (Illinois) region, to appear in a subsequent 

 paper of this volume of the Laboratory Bulletin. 



2. THE relations OE ANIMALS TO THEIR ENVIRONMENT 



The study of animal ecology may be taken up from many sides and 

 in many ways. One of the most interesting and fundamental of these 

 is that which considers the dependence of the animal upon its environ- 

 ment, and at the same time orients it in the gamut of energies and 

 substances. Many phases of this discussion, though elementary and 

 for this reason easily overlooked, are yet of fundamental importance. 

 Every boy who has kept pets in confinement, and who has had the re- 



