Chap. VIII.] INSTINCT. 321 



benefit from this, it was much embarrassed, 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 already finished work. 



If we suppose any habitual action to become inherited 

 — 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 dis- 

 tinguished. 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 genera- 

 tion, and then transmitted by inheritance to succeeding 

 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 

 selection 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 

 wonderful 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 



