580 H. S. 'Jennings 



mental investigation, exactly as are other physiological processes. 

 There is the same reason to suppose them detectible by chemico- 

 physical means as in the rest of physiology. There is indeed no 

 reason for making any distinction in principle between these and 

 the processes of movement or metabolism. The investigator in 

 this field simply w^orks on a part of the domain of physiology which 

 has been mainly cultivated independently of the remainder of 

 that science. In no way is the study of racial processes to be so 

 much advanced as by considering this field, what it really is, a 

 constituent part of physiology, and by attacking it from the same 

 standpoints that have proved their worth in the rest of this science. 

 Study of essentially this character is well underway in the work of 

 the modern students of heredity — Bateson, De Vries, Davenport, 

 Tower, Herbst, and others — though the point of departure has 

 been in most cases not primarily physiological. 



The special methods used — the technique — in a physiological 

 investigation of racial processes will of course be extremely dif- 

 ferent from those of an investigation of metabolism or contrac- 

 tility; it is only in fundamentals that the method of attack must 

 be the same. Every problem requires its own technique. In 

 the study of racial processes we have to deal with certain problems 

 and phenomena which have as a rule not been looked at from a 

 physiological point of view. They are nevertheless physiological 

 matters, and need restatement in physiological terms. Let us 

 attempt this: 



Evolution, from this standpoint, is a general name for the physio- 

 logical processes which result in change of characteristics from 

 generation to generation. The physiological study of evolution 

 is the objective and experimental investigation of these processes. 



Adaptiveness, purposiveness, teleology, etc., are concepts based 

 on the observed phenomena that the characteristics of organisms 

 are largely of such a nature as to maintain the processes which we 

 call life, and thus keep the organisms in existence. From a purely 

 physiological point of view the teleological problem is essentially 

 this: How does it happen that combinations of such complexity 



