vi INSTINCT 89 



" I once watched one (/>., a cobra) which had thrust its head 

 through a narrow aperture and swallowed one (/'.*., a toad). 

 With this encumbrance he could not withdraw himself. Finding 

 this, he reluctantly disgorged the precious morsel, which began to 

 move off. This was too much for snake philosophy to bear, and 

 the toad was again seized ; and again, after violent efforts to 

 escape, was the snake compelled to part with it. This time, 

 however, a lesson had been learnt, and the toad was seized by one 

 leg, withdrawn, and then swallowed in triumph." l 



Here there appears a sort of conflict between the impulse 

 to seize, and the necessity of withdrawing the head. The 

 result is a kind of compromise which happens to suit the 

 case well. The toad is seized, but the swallowing reflex 

 is kept in abeyance till the withdrawal is performed. 

 Without dogmatising about this particular instance, one 

 sees how the conflict of impulses may work out to a 

 harmony : how different stimuli, each severally exciting an 

 unsuitable reflex, may act upon and so modify one another 

 as to produce the required adjustment. Where each 

 stimulus acts alone, we get the pure reflex. Where they 

 act together we may get merely an adjustment produced 

 by mutual modification, but where their action is not once 

 nor twice but frequently so combined as to adjust itself to 

 the peculiarities of an outer object, we have sensor i-motor 

 action. Where sensori-motors and reflexes are combined 

 in series so as to lead to a definite result, though this 

 result is not foreseen, we have instinct. Where, finally, 

 it is impossible to explain the act except as determined by 

 relation to an end beyond the compass of sensori-motor 

 response, we must impute intelligence. Now the basis of 

 instinct is heredity, but in sensori-motor action we have 

 a factor which is not purely hereditary, namely, the com- 

 bination of data by present consciousness. We shall use 

 the term " pure instinct " for all behaviour that depends 

 upon these elements alone, and shall contrast them with 

 instincts that involve intelligence, meaning by intelligence 

 processes which the individual devises for himself upon 

 the basis of his own experience. Of intelligence operating 

 within the sphere of instinct there is ample evidence. There 

 are modifications of instinctive action directly traceable 

 1 Romanes, p. 262. 



