DO FISHES THINK?

Evening Post, Volume CXXIV, Issue 111, 6 November 1937, Page 27

DO FISHES THINK?

"A few, weeks ago I was asked by a companion, 'Do fishes think?' and 1 countered him with 'What do you mean by thought?'" said Professor Gray at the British Association's annual meeting, says the "Daily Telegraph.'l

It soon became clear that my companion was, in fact', wondering how far the outward behaviour of the fish depended on its memory of past events. and how far the concepts of home and fear, pleasure and pain, formed crossroads in the life of a fish as real to it a 1 they are to man in his'ev.eryday life. Memory and emotion are essentially conscious phenomena, and it .is obvious that if we could show that a fish remembers the past or has an appreciation of 'beauty, we could soon decide that it if capable of thought.

"I am inclined. to doubt how far any of the movements exhibited by a fish when subjected to casual observation need involve any conception other than that of rigid reflexes. The fish may be conscious of its movements, but] there is no particular reason why he should.

We may now consider how far, if at all, we can educate a fish in the sense that we can induce it to make mental associations. This possibility, has been realised for. many centuries, for we have authentic accounts of' carp coming to, be fed by the monks when a bell: was rung near the ponds. It is only within recent years, however, that the problem has been subjected to rigid scientific investigation. .

Experiments show conclusively that the fish have learned to associate the ringing of the bell with the arrival of food—just as we do ourselves. ,

What type of comrJass, Professor

Gray asked, does the adult fish use to reach its breeding-ground? The whole phenomenon is shrouded with mystery. Does the adult fish retrace by memory the movements of its youth? Are there subtly changes in the chemical or physical properties of the. \vater-all. across the Atlantic which" guide the fish automatically? We do not know.

Alternatively, it has been suggested that the outward migration; is along a prehistoric river system, leading con-: tinuously to deeper water; but, in that case, what guides the young fish';back" to the rivers? At present we vhave no convincing explanation of the facts, and we must pause before concluding that in the realm of navigation "man takes a higher place.than the eel. -

Experiments, carried out in- the Pacific show that the Pacific salmon is able, to, retrace us path of many hundreds of miles and reach, with what can only be called uncanny instinct, the river of Its childhood; •».,,■■■■■': '

How are we to explain, this feat of navigation? Has the salmon a sense of direction, or does he k«ep near, the bottom carefully recording the landmarks .as he goes, so that he is able to retrace his path? .

I, venture to think,. added .Professor Gray,'-that'if we were to have carrier out comparable experiments on a raca of human beings and got similar resuits, we would have said: They do it as you or I would do it, consciously noting the "landmarks, memorising them, and so retracing their steps; in fact, they are performing, a conscious, premeditated, thoughtfnl, and- purposive, act. Are we ,to, -apply the same conclusions to the fish? If- not why not?S : ' ; • ■'- ■-.- : •---■-. ~ ■;