394 PSYCHOLOGY. 



instincts ; all would come to light without perversion or 

 disguise. But there are no such abstract animals, and no- 

 where does the instinctive life display itself in such a way. 

 Not only, as we have seen, may objects of the same class 

 arouse reactions of opposite sorts in consequence of slight 

 changes in the circumstances, in the individual object, or in 

 the agent's inward condition ; but two other principles of 

 which we have not yet spoken, may come into play and 

 produce results so striking that observers as eminent as 

 Messrs. D. A. Spalding and Romanes do not hesitate to 

 call them 'derangements of the mental constitution,' and 

 to conclude that the instinctive machinery has got out 

 of gear. 



These principles are those 



1. Of the inhibition of instincts hy habits; and 



2. Of the transitoriness of instincts. 



Taken in conjunction with the two former principles — 

 that the same object may excite ambiguous impulses, or sug- 

 gest an impulse different from that which it excites, by sug- 

 gesting a remote object — they explain any amount of de- 

 parture from uniformity of conduct, without implying any 

 getting out of gear of the elementary impulses from which 

 the conduct flows. 



1. The law of inhibition of instincts by habits is this : 

 When objects of a certain class elicit from an animal a certain 

 sort of reaction, it often happens that the ayiimal becomes partial 

 to tlie first specimen of the class on which it has reacted, and ivill 

 not afterward react on any other specimen. 



The selection of a particular hole to live in, of a partic- 

 ular mate, of a particular feeding-ground, a particular variety 

 of diet, a particular anything, in short, out of a possible multi- 

 tude, is a very wide-spread tendency among animals, even 

 those low down in the scale. The limpet will return to the 

 same sticking-place in its rock, and the lobster to its favorite 

 nook on the sea-bottom. The rabbit will deposit its dung in 

 the same corner ; the bird makes its nest on the same bough. 

 But each of these preferences carries with it an insensibility 

 to other opportunities and occasions — an insensibility which 

 can only be described physiologically as an inhibition oi 



