CHAPTER VII 



INSTINCT AND DISCERNMENT 



' I *HE Pelopsus gives us a very poor idea 

 of her intellect when she plasters the 

 spot in the wall where the nest which I have 

 removed used to stand, when she persists in 

 cramming her cell with Spiders for the 

 benefit of an egg no longer there and when 

 she dutifully closes a cell which my tweezers, 

 extracting both germ and provisions, have 

 left empty. The Mason-bees, the caterpil- 

 lar of the Great Peacock Moth and many 

 others, when subjected to similar tests, are 

 guilty of the same illogical behaviour: they 

 continue, in the normal order, their series 

 of industrious actions, though an accident 

 has now rendered these useless. Just like 

 mill-stones, which do not cease revolving 

 though there be no corn left to grind, let them 

 once be given the compelling power and they 

 will continue to perform their task despite its 

 futility. Are they then machines? Far be 

 it from me to think anything so foolish. 

 It is impossible to make definite progress 

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