THE EVOLUTION OF ANIMAL 

 INTELLIGENCE 



CHAPTER I 

 INTRODUCTION 



"If the doctrine of Evolution is true, the inevitable implication 

 is that Mind can be understood only by observing how Mind is 

 evolved." HERBERT SPENCER, Principles of Psychology. 



" Alle instinktiven Triebe und zweckbewussten Willensausserungen 

 dienen entweder der Erhaltung des eigen Lebens oder der Erzeugung 

 und Pflege der Nachkommenschaft." SCHNEIDER, Der Thierische 

 Wille. 



"Si la fc psychologie humaine est le*gitime, la psychologic compare'e 

 Test aussi, pour les memes raisons." CLAPAREDE. 



In the last two decades the science of animal psychology 

 has had an unprecedented development. Previous to this 

 time and subsequent to the appearance of the Origin of 

 Species students of the animal mind were concerned in 

 bringing forward proofs of the similarity of the mental 

 processes of men and animals and in tracing the gradual 

 unfolding of the mental powers in passing from lower to 

 higher forms. The followers of Darwin in their efforts to 

 show that evolution is applicable in the mental as well as the 

 physical world were naturally prone to minimize the gulf 

 separating the human and the animal mind which the tradi- 

 tional psychology had formerly taught was a wide and im- 

 passible one. 



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