vi NEWLY-HATCHED CHICKS 245 



experience, that is, by intelligence and not by instinct, are 

 far surpassed by others which are known ; but I have pre- 

 ferred, as everywhere else in this book, to use new examples 

 which have come under my own observation. 



EXPERIMENTS AND OBSERVATIONS ON INSTINCT IN 

 NEWLY-HATCHED CHICKENS 



Last year I had some chickens hatched in an incubating 

 apparatus. They had never seen a mother, and were never 

 taught to seek food. I placed some millet seed in front of 

 them in a vessel; they took no notice of it. Then I took 

 some of the seed in my hand and let it fall on the hard 

 wooden floor so that the grains rebounded. The chickens 

 then at once pecked at it, and in a short time fed without 

 assistance. But the thing that surprised me most was this : 

 a fly flew close by the eyes of a chicken which had only left 

 the egg-shell about half an hour before, and the little creature 

 pecked at it as if it had been long accustomed to catch flies. 

 Similar cases have indeed been frequently observed. 



It may be objected that this was nothing but simple reflex 

 action and of course it is reflex action. But the wonderful 

 fact is that this action was so perfectly adapted to the external 

 requirements ; the chick snapped at the fly in order to catch 

 it ; it made with accuracy all the movements suited to this 

 purpose. If it had caught the fly, it would have bitten it up 

 and eaten it as it ate the millet. It had evidently brought 

 into the world, in its brain, a mechanism which included an 

 inherited mental image of the flight of a fly, an inheritance of 

 the effect of the stimulation which flies have exerted upon its 

 ancestors during their life for ages past. A proof of this is 

 that the same chicken responded quite differently to other 

 similar stimuli acting on its eyes, e.g. to a rapid movement 

 of the fingers. In short, the chicken's behaviour towards the 



