INFLUENCE OF ENVIRONMENT 345 



ted as such to its descendents it was customary 

 to speak of developed characters as heredi- 

 tary or acquired and to talk of the inheritance 

 or non-inheritance of acquired characters. 

 This distinction is not a logical one for all 

 developed characters are invariably the result 

 of the responses of the germinal organi- 

 zation to environmental stimuli; and of course 

 no developed character can be purely heredi- 

 tary or purely environmental. But when a 

 given character arises in many individuals of 

 the same genotype under different environ- 

 mental conditions it is probable that heredity, 

 which is the constant factor in this case, is also 

 the determining factor for that character. On 

 the other hand if a character develops in re- 

 sponse to peculiar stimuli and does not appear 

 in other individuals of the same genotype in 

 which such stimuli are lacking it is said to be 

 an environmental or acquired character. In 

 fine inherited characters are those whose dis- 

 tinctive or differential causes are in the germ 

 cells , while acquired characters are those 

 whose differential causes are environmental. 

 Briefly stated the question of the inheritance 



