18 



on zoology and search for a comprehensive and adequate recognition 

 and utilization of the orderly and regulatory character of the environ- 

 ment as an essential part of the subject. 



The fallacy of this position has been well expressed as follows by 

 Brooks ('99) : "I shall try to show that life is response to the order of 

 nature. . . . But if it be admitted, it follows that biology is the study 

 of response, and that the study of that order of nature to which re- 

 sponse is made is as well within its province as the study of the living 

 organism which responds, for all the knowledge we can get of both 

 these aspects of nature is needed as a preparation for the study of 

 that relation between them which constitute life." Later he says : "But 

 if we stop there, neglecting the relation of the living being to its en- 

 vironment, our study is not biology or the science of life." No one 

 seems to have attempted to refute this ; naturally an easier path is fol- 

 lowed — to ignore it. Perhaps up to the time of the present generation 

 there has been some excuse for this confusion; l)ut now the respon- 

 sibility does not rest upon students of the physical and vegetational en- 

 vironment but upon students of animals, because the former students 

 have arranged their scientific data in a manner which clearly shows 

 the orderly lawful sequence of changes in environmental activities. 

 This should form the basis for a study of the corresponding series of 

 changes which take place within the animal, and also be the basis for 

 a study of the reciprocal responses taking place between the animal and 

 the environment. 



In this section an outline will be given of some of the most impor- 

 tant phases of environmental changes in inland areas viewed as lawful 

 and orderly, particularly those changes which influence animal hab- 

 itats. 



2. THE DYNAMIC AND GENETIC STANDPOINT 



Since Lyell taught the scientific world that a study of processes 

 now in operation is the key to an understanding of the present as well 

 as of the past, the process method has been slowly but inevitably pene- 

 trating to the utmost subdivisions of inquiry. With the progressive 

 appreciation and use of this method its efficiency has been increased. 

 Its progress has been the most rapid where the principles of its appli- 

 cation have been most clearly understood. As models become known 

 in each field of work others will find the method much easier to apply, 

 and for this reason it is desirable that such examples become fairly 

 numerous and wide-spread. 



In the application of the process method to an imperfectly under- 

 stood subject, and particularly to a complex one, it is desirable to con- 

 sider the subject as a imit or entity. This unit may then be regarded 

 as an agent whose process of activity is to be studied, for the activity 



