vii ASSIMILATION AND READJUSTMENT 135 



mental operation than those hitherto described. But in the 

 absence of details, one would be inclined to think that in 

 such cases the older fish are of the more wary type which 

 under the circumstances has survived. Of each new gener- 

 ation, at least for a long period, a great number would 

 always be of the less wary type, and these would be caught. 

 The more waters are fished, the more the young are likely 

 to preponderate among those caught. For, taking any 

 single generation, the least wary will be most caught at 

 each fishing, so that the more wary will preponderate more 

 and more, whence, in subsequent fishings, that generation 

 will have an advantage over the younger ones. At the 

 same time fish show a good deal of " caution," i.e. y they 

 examine strange objects and approach them tentatively. 

 Schneider notes this of the mullet and parrot-fish precisely 

 in relation to baits. There is therefore a certain basis for 

 experience to work upon. If, in the course of such inves- 

 tigation, a fish is frightened, say by the shadow of the 

 fisherman, it will be still more cautious next time. Thus 

 the increase of wariness may be due purely to the elimina- 

 tion of the unwary, or it may be assisted by frightening 

 experiences. But there seems no reason to attribute it to 

 an articulate, analogical inference. 



Many fish are, however, capable of being guided by 

 experience in the elementary form described above (p. 

 in ff.). They have the sort of instincts that must be 

 concentrated on particular objects, and this implies that 

 their experience in relation to those objects has some more 

 or less persistent effect upon them. For example, they 

 have haunts, and in some cases homes. The shark haunts 

 places that it has found to be good hunting grounds. 1 

 The stickleback " knows the way " back to his nest, even 

 if he has been absent for some hours. 2 Evidently we have 

 here the operation of experience in some form. What sort 

 of experience is it ? Is it accurate to attribute to the fish 

 definite memory of the place and knowledge of its relations 

 in space ? Or shall we be right in explaining its return to 

 its haunts as due to those workings of experience on per- 

 ception, and through perception on motor impulse, which 



1 Brehm, VIII. p. 440. Cf. Schneider, p. 312. 2 Ib. p. 171. 



