Chap. VIII.] iNSTlNOT. 3^1 



was much emtarrassed, and in order to complete its 

 hammock, seemed forced to start from the third stage, 

 where it had left off, and thus tried to complete the al- 

 ready finished work. 



If we suppose any habitual action to become in- 

 herited — and it can be shown that this does sometimes 

 happen — then the resemblance between what originally 

 was a habit and an instinct becomes so close as not to 

 be distinguished. If Mozart, instead of playing the 

 pianoforte at three years old with wonderfully little 

 practice, had played a tune with no practice at all, he 

 might truly be said to have done so instinctively. But 

 it would be a serious error to suppose that the greater 

 number of instincts have been acquired by habit in one 

 generation, and then transmitted by inheritance to suc- 

 ceeding generations. It can be clearly shown that the 

 most wonderful instincts with which we are acquainted, 

 namely, those of the hive-bee and of many ants, could 

 not possibly have been acquired by habit. 



It will be universally admitted • that instincts are as 

 important as corporeal structures for the welfare of each 

 species, under its present conditions of life. Under 

 changed conditions of life, it is at least possible that 

 slight modifications of instinct might be profitable to a 

 species; and if it can be shown that instincts do vary 

 ever so little, then I can see no difficulty in natural se- 

 lection preserving and continually accumulating vari- 

 ations of instinct to any extent that was profitable. It 

 is thus, as I believe, that all the most complex and won- 

 derful instincts have originated. As modifications of 

 corporeal structure arise from, and are increased by, 

 use or habit, and are diminished or lost by disuse, so I 

 do not doubt it has been with instincts. But I believe 



