LAWS OF INTERNAL CHANGE 93 



orderly sequence," by its processes of metabolism, 

 both energy and substance, resulting in growth, 

 differentiation, multiplication, and behavior. These 

 activities take place in an orderly manner and are 

 dependent upon both energy and substance derived 

 from the environment. For these reasons the 

 processes or changes in metabolism, growth, develop- 

 ment, and behavior, in so far as they are responses 

 to the orderly sequence of environmental changes, are 

 ecological problems. The changes in behavior during 

 the life of the animal or the development of its 

 behavior give one of the main clues to the physio- 

 logical conditions which determine some of the most 

 characteristic forms of responses, and finally as a 

 result of all these activities and processes of adjust- 

 ment to the conditions of life, a relatively mature and 

 adjusted condition of the struggle for existence in 

 animals and associations may be reached, the cul- 

 mination of animal harmonies. For this reason 

 studies in modifications of behavior are of fundamen- 

 tal ecological importance, because they consider 

 behavior not only as ready-made, but also in the 

 process of making. Such considerations as these 

 make it desirable to include some of the most valuable 

 and suggestive books and papers which deal with those 

 general physiological processes influencing growth, 

 development, multiplication, and behavior, and 

 particularly those which aid one in realizing their 

 order or successive changes, or "orderly sequence." 



In studying the activities of the individual animal, 

 the normal environment to which it is attuned 



