Edinger, Comparative Psychology. 443 



fish doubtless serves for all the receptions necessary to the animal, 

 for all regulations, and for all the movements which the animal's 

 relation to the outside w^orld demands, that is, for locomotion, for 

 obtaining food, and for the reproductive activities. Not only all 

 the activities which we commonly designate as reflex, but also all 

 instincts, are localized in the palaeencephalon. Flight when sur- 

 prised, migrations, nest-building, courtship, and many other activ- 

 ities are to be observed in the bony fishes. 



On theoretical grounds it has particularly interested me to ascer- 

 tain if fishes learn. From my own observations, from the litera- 

 ture, and from hundreds of contributions which I have received 

 in response to an inquiry, it is now well established that new kinds 

 of receptions, provided that they afi^ect the inherited motor mechan- 

 isms with sufficient intensity or sufficiently often, stimulate them. 

 The animals learn in a very moderate degree to modify their ac- 

 tivities. One can tame them, and train them not to flee, so that 

 they allow themselves to he held in the hand; or they may be 

 called to food at a certain place or a certain time. They can learn 

 to swim to a particular person who feeds them. These associa- 

 tions become so well established that, for example, my Macropoda, 

 which I never feed myself, swim up as soon as I appear because, 

 five months before, they had always been fed by anyone who 

 approached. A pike which has several times escaped the spear 

 becomes more cautious and learns to avoid it. But fishes always 

 return to the hook so long as the bait presents the same appearance, 

 for it is not the fish which attracts the prey but the prey which 

 attracts the fish. If the bait is unusual in appearance it does not 

 attract. All the experience of anglers goes to show that fish will 

 not go to poorly arranged bait. That, however, does not neces- 

 sarily indicate intelhgence, for if they possessed the genuine 

 intelligence which has occasionally been attributed to fishes, we 

 should expect that sometimes they would be caught by inappro- 

 priate bait. As a rule fishes respond to particular sensory stimuli 

 by the execution of certain definite combinations of movements. 

 But their brain is able to relate a new sense impression with a 

 movement combination which formerly had not answered to it. 

 I propose to designate this lowest kind of association by the term 

 establishing of relations, but to reserve the term connecting of 

 associations for those totally diff'erent processes of the brain which 

 we observe after the appearance of the neencephalon. Such very 



