226 RALPH S. LILLIE AND EARL N. JOHNSTON. 



to it in a manner which cannot be precisely defined at present. 

 Evidently structure, as such, in the sense of fixed disposition of 

 material parts, represents only one side of the vital organization; 

 its other and more characteristic side is manifested in the various 

 special organic processes and the external behavior of the or- 

 ganism; these in turn imply the regulated concurrence, interaction 

 and sequence of numerous simpler processes and events of a 

 purely physico-chemical nature. 



It is necessary, therefore, in forming a conception of the vital 

 organization, to include as elements all of those constant or 

 regularly recurrent features, both of structure and of activity, 

 which contribute to the persistence or stability of the organism, 

 considered as an individualized part of nature i. e., as a system 

 in equilibrium with an environment. Any living being repre- 

 sents an integration or unification not merely of static conditions 

 like structure, but also of processes, both simultaneous and suc- 

 cessive; i. e., the organism is to be considered not simply as a 

 physical whole which is complete at any given moment, but rather 

 as in its essential nature an ordered or regulated sequence of 

 changes and activities, coordinated in space and time. For 

 example, the succession of formative and physiological processes 

 constituting development, or any special instinct requiring time 

 for its exercise, is just as constant and characteristic a feature of 

 the organization of a species as is its skeletal structure. What 

 is most remarkable in the organism is the exact coordination of 

 the various single activities, widely separated as they often are 

 both spatially and temporally. Simultaneity in certain pro- 

 cesses, ordered, succession in others, are equally essential to its 

 stable working; to be concrete, the normal activity of the heart 

 and circulation in higher animals requires the simultaneous and 

 coordinated activity of the nervous system, and the process of 

 digestion depends upon the constancy of a certain definite suc- 

 cession of events in the alimentary tract and its related organs. 

 All of this must be remembered in considering the problem of 

 organic growth; we have to account for the construction of a 

 system which is complex and specific in its activities, as well as 

 in its structure. 



It will be agreed that the possibility of any special organic 



