CHAPTER VI 



Heredity and Instinct (H.)^ 



In the preceding chapter I argued from certain psycho- 

 logical truths for the position that two general principles 

 recently urged by Romanes for the Lamarckian, or * inher- 

 ited habit,' view of the origin of instincts do not really sup- 

 port that doctrine. These two principles are those cited by 

 Romanes under the phrases respectively ' co-adaptation ' 

 and 'selective value.' In the case of complex instincts 

 these two arguments really amount to but one, so long as ' 

 we are talking about the origin of instinct. And the one 

 argument is this : that partial co-adaptations in the direc- 

 tion of an instinct are not of selective value ; hence instinct 

 could not have arisen by gradual partial co-adaptive varia- 

 tions, but must have been acquired by intelligence and 

 then inherited. This general position is dealt with in the 

 earlier chapter. 



It will be remembered, however, that the force of the refu- 

 tation of the Lamarckian's argument on this point depends 

 on the assumption, made in common with him, that some 

 degree of intelligence or imitative faculty is present before 

 the completion of the instinct in question. To deny this is, 

 of course, to deny the contention that instinct is ' lapsed 

 intelligence,' or * inherited habit.' To assume it, however, 

 opens the way for certain further questions, which I may now 

 take up briefly, citing Romanes by preference as before. 



^ Conclusion of the preceding paper, printed separately in Science, April 

 lo, 1896. 



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