228 INSTINCT. 



reason. Habits easily become associate with other habits, 

 with certain periods of time and states of the body. When 

 once acquired, they often remain constant throughout life. 

 Several other points of resemblance between instincts and 

 habits could be pointed out. As in repeating a well-known 

 song, so in instincts, one action follows another by a sort of 

 rhythm ; if a person be interrupted in a song, or in repeat- 

 ing anything by rote, he is generally forced to go back to 

 recover the habitual train of thought ; so P. Huber found it 

 was with a caterpillar, which makes a very complicated 

 hammock ; for if he took a caterpillar which had completed 

 its hammock up to, say, the sixth stage of construction, and 

 put it into a hammock completed up only to the third stage, 

 the caterpillar simply re-performed the fourth, fifth and 

 sixth stages of construction. If, however, a caterpillar 

 were taken out of a hammock made up, for instance, to 

 the third stage, and were put into one finished up to the 

 sixth stage, so that much of its work was already done for 

 it, far from deriving any 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 aetion 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 distinguished. 

 If Mozart, instead of playing the piano-forte 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 inherit- 

 ance to succeeding generations. It can be clearly shown 

 that the most wonderful instincts with which we are ac- 

 quainted, 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 im- 

 portant 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 modifica- 

 tions 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 con- 

 tinually accumulating variations of instinqt to any extent? 



