The digestive canal represents a tube passing through the entire organism and communicating with the external world, i.e. as it were the external surface of the body, but turned inwards and thus hidden in the organism.
-- Ivan Pavlov
   
Ivan Pavlov   Name:
Ivan Pavlov
Type:
Psychologist
Nationality:
Russian
Birth:
September 14, 1849
Death:
February 27, 1936
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