332 Habit and Instinct. 



direct evidence ; and the structural question * does not call 

 for discussion here. 



It would seem, then, that of acquired habit passing into 

 congenital instinct of demonstrable definiteness, there is 

 but ■ little, if any, reliable evidence of a crucial kind. 

 We must therefore turn to the other aspect of heredity 

 — that which has reference to innate power or faculty — 

 and must ask whether there is any such marked increase 

 of inborn capacity as may reasonably be attributed to 

 direct transmission of acquired increments of faculty. 



It must here be remembered that innate capacity affords 

 to the individual what is at first a relatively unspecialized 

 power of dealing with the particular conditions of indi- 

 vidual life as they are presented to experience. The 

 amount and quality of this innate capacity unquestionably 

 varies in different individuals. Its specialization and the 

 particular mode of its application are determined by the 

 conditions of individual development, and the environment 

 to which there is need of adaptation. This serves to dis- 

 tinguish innate capacity, the definite application of which 

 is acquired in the course of individual life, from the con- 

 genitally determined adaptiveness of instinctive behaviour. 

 The distinction was illustrated in our introductory chapter 

 by an analogy drawn from the familiar facts of the inheri- 

 tance of wealth. That which is instinctive was likened 

 to the inheritance of specific drafts for particular, and 

 relatively definite purposes in the conduct of life, over the 

 initial application of which the individual is given no 

 control ; innate capacity to the inheritance of a legacy 

 which may be drawn upon for any purpose as need arises. 



* Dr. Gustav EetziuB has shown ("Biologishe Untersuohungen," neue 

 FolgK, vii. 1895) that the modifications of stracture due to civilized habit 

 (e.g. the use of chairs) are not inherited, the foetus retaining the ancestral 

 condition. His arguments for transmission of habit appear to take little 

 account of the effects of tradition. 



