vii ASSIMILATION AND READJUSTMENT 129 



doubtedly formed, and it would be interesting to get some 

 detailed account of the way in which they are formed, 

 particularly among animals of no very great intelligence. 

 I do not know of any decisive evidence on this point, and 

 I must, therefore, let this third explanation stand as a 

 possibility, even in the case of somewhat lengthy trains of 



association. 1 



8. Of the three explanations offered, the second and 

 third, though different in detail, are alike in principle. Both 

 dispense with any intelligent apprehension of the relation 

 between act and consequence, and trace the genesis of a 

 response to the power of an excitation to absorb into itself 

 or assimilate the motor tendencies or feelings with which 

 it is intimately associated. Since this simpler explanation 

 covers the facts, we have no right, on the strength of mere 

 modification of response to stimulus alone, to impute the 

 higher degree of intelligence suggested by the first expla- 

 nation. It is no doubt natural to explain an alteration of 

 behaviour towards an object by saying that the animal re- 

 members the results of previous action, and infers that 

 similar results will follow in a fresh case. It may seem a 

 still more modest assumption if we explain that the ideas of 

 two objects or two qualities of keeper and food, or black 

 and yellow stripes and nasty taste have become associated 

 in the animal's mind. But a little consideration of our 

 own human experience will show that even this explanation 

 goes further than is warranted by the facts. In ordinary 

 perception we are, as a rule, in direct contact through our 

 sense organs with only one or two qualities of the objects 



the same tentacle each time. As a rule the fragment was carried to the 

 mouth, swallowed, and then ejected. "After a few days, the number 

 varying in different individuals from two to five days, the fragment is no 

 longer swallowed, and in about another two days the tentacles will no 

 longer take hold of it." Thus the inhibition first affects the mouth and 

 spreads from it to the tentacle. But, further, though the tentacle itself 

 with the part of the mouth attached has now learnt the lesson, other 

 tentacles on the opposite side can still be deceived once or twice, though 

 they learn more speedily on account of the education which the first 

 tentacles have received. Here then we have a case of a very simple 

 inhibition affecting different parts of the organism by successive stages. 



1 It is an obvious corollary from the third explanation that the remoter 

 association can only be formed by slow degrees. This accords well with 

 the facts in the lower grades of intelligence. 



