HAVE FISHES MEMORY. 377 



happen upon the mighty nerve path leading from the primary termini 

 of the nerve of vision to the cortex. The latter fact at once explains 

 why the sight of birds is psychically far better developed than that of 

 other animals. The bird of prey hovers hundreds of meters above the 

 surface of the earth, yet when he darts down he is never mistaken — he 

 has recognized a little mouse as one of his tidbits known from of old. 

 Birds can not be lured with bait. Of all animals birds alone can be 

 frightened oif permanently by means appealing to the eye; only for 

 them scarecrows, made to appear as like human beings as possible, are 

 set up in the iields. 



At best we have not advanced beyond the initial steps in this branch 

 of science, but the road open to travel is becoming visible. Of one 

 thing, however, we are wholly ignorant — of the role played in psychic 

 processes by the ganglia, the centers in which the nerves of sense end, 

 the primary termini, in other words. Do they, too, retain impressions ? 

 Do paths issue also from them rendering previous sensations available 

 for later actions? Is the function of memory confined to the cortex, 

 or does it appertain equally to the interior parts of the brain? If the 

 latter is true, another question at once arises: What gain accrues to 

 the psychic life from the activity of the cortex? 



An approach to the solution of these questions has been made, it is 

 hoped, by an inquiry conducted by me during the year 1897. It was 

 important that I should have an abundance of observations at my dis- 

 posal. The following appeal was therefore sent to a number of jour- 

 nals devoted to fishery and aquarium interests and to some scientific 

 publications at home and abroad, and much to my satisfaction it was 

 copied in the daily press. 



"have fishes memory? 



"^4. request for information. 



"It has been generally assumed that to a certain degree fishes pos- 

 sess memory, that they know persons, that they are able to find or 

 avoid spots in which their experiences have been pleasant or the reverse, 

 and, having once escaped the hook, they thereafter recognize it, etc. 



"The advance of psychology makes it desirable that pertinent expe- 

 riences should be collected for the following reason: Up to the present 

 time the opinion has prevailed that the function of memory is mainly 

 dependent upon the presence of th& cortex of the brain. Of the part 

 played in this particular by the inner portions of the brain we know 

 nothing. Scientists have succeeded in demonstrating that the brain of 

 fishes lacks the slightest trace of cortical substance. If, now, it can 

 be proved beyond the shadow of a doubt that these animals gather 

 experiences and apply them to subsequent situations — that, in other 

 words, they possess memory — then the accepted doctrine, that only the 

 cortical substance of the brain confers the power of memory, falls to 

 the ground, and entirely new problems face the scientist. 



