44^ Eimer on Growth and Inheritance 



Certain observations made by the Professor with respect 

 to chickens newly hatched seem to us to be valuable. To 

 some which had been artificially hatched he threw a little 

 millet-seed, letting it fall so that the grains rebounded. The 

 chickens at once pecked at it ; but he adds : ^ — 



* The thing which surprised me most was this : A fly flew close by 

 the eyes of a chicken Avhich 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 reflex action 

 — and of course it is reflex action. ^ But the wonderful fact is, that 

 that 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. ... In short, the 

 chicken's behaviour towards the fly was a consequence of innate 

 instinct, like that of itself and brethren towards the millet-seed.' 



The merely instinctive, as opposed to intellectually pur- 

 posive, actions of these chicks, was shown by their scratching 

 on boards (which formed the first surface they walked on) 

 just as mature fowls scratch in sand or earth in search of 

 food. 



' To see them scratching on the smooth board, from which there 

 was nothing to scratch out, was exceeding comical.' 



His view of instinct is, as before said, that it consists of 

 truly rational actions which have become habitual, and is 

 therefore absolutely opposed to that of Professor Weismann, 

 who regards it as the result of merely minute accidental 

 changes in the molecules of germ-plasm. But, as Professor 

 Eimer pertinently asks,^ 'How is it conceivable that the 

 variability of germ-plasm, inherited from unicellular organ- 

 isms, in combination with continued sexual mixture, could 



1 P. 245. 



- The term ' reflex action ' should be reserved for motor responses to 

 stimuli which are not felt. Such reflex action as the chicken's is ' sensori 

 motor ' action. ^ P. 253. 



