ANIMAL AND PLANT INTELLIGENCE 



ical than by a psychological gulf. His anatomy 

 is fundamentally the same, though there is doubt- 

 less an invisible gulf in the molecules of the brain 

 cells ; but his psychology is fundamentally different. 

 Is this difference any greater, it may be asked, 

 than that which separates the highest human in- 

 telligence from that of the lowest savage? I look 

 upon it more as a difference of kind than of degree. 

 It is comparatively easy to trace a continuous line 

 of development from the mind of the Hottentot to 

 the mind of the foremost European, but between 

 the savage and our pithecoid ancestors there are 

 many missing links. The evolutionary process that 

 must have connected them has worked out some- 

 thing like a metamorphosis. 



Darwin in seeking to prove the animal origin of 

 man felt called upon to show at least the rudiments 

 of man's reasoning powers in his humbler begin- 

 nings. Certain it is that evolution must have some- 

 thing to go upon. But does it not have enough to 

 go upon in the kind of intelligence the unthinking 

 animal world exhibits? The slow metamorphosis 

 of this into human reason is no more difficult to 

 conceive of than a hundred other slow metamor- 

 phoses that may be traced in nature, wherein we 

 see the adult animal totally unlike its youthful 

 beginning, or where we see two chemical elements 

 uniting to form a third entirely unlike either. Ani- 

 mal and vegetable life doubtless had a common 

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