Animal Psychology, the Old and the New 23 



Ings of LeRoy. Lamarck regarded the evolution 

 of animals as brought about, to a very large extent, 

 by psychic factors. His three primary divisions of 

 the animal kingdom, the apathetic, the sensitive and 

 the intelligent animals, are based on psychological 

 distinctions. The apathetic animals, such as the in- 

 fusoria, polyps, etc., are, like plants, irritable, but 

 devoid of consciousness and spontaneity. The tran- 

 sition from the apathetic to^ the sensitive animals 

 comes with the development of a nervous system 

 which was erroneously regarded as absent in some of 

 the higher members of the apathetic group. Con- 

 sciousness first appears in a vague form, but as or- 

 ganization advances and the nervous system and 

 sense organs become more specialized and perfected, 

 consciousness comes to assume more of a guiding 

 role in the process of evolution. Everywhere con- 

 sciousness is considered by Lamarck as dependent 

 upon the organization of the nervous system, but 

 as he is an "interactionist" he regards the activities 

 of anima.ls as initiated to a large extent by their feel- 

 ings and desires. 



As Is well known, Lamarck explained instinct as 

 inherited habit; but habits depend upon antecedent 

 desires of the animal; these lead to efforts by which 

 the desires may be satisfied, and by frequent repe- 

 tition the acts thus prompted become habitual and 

 are passed on as inherited proclivities to following 

 generations. 



With the appearance of wants determination of 



