Allex, Association in the Guinea Pig. 339 



V. The Psychic Life of the Guinea Pig Compared luit/i that 

 of the White Rat. 



The Use of the Senses. — With the white rat, in the search 

 for food, the sense of smell is paramount.^ Smell is by far the 

 most necessary sense in the life economy. This sense does not 

 play nearly so important a part with the guinea pig. It is an 

 efficient sensation, but is apparently neither a definite nor a 

 strong incitement to reaction. 



As with the guinea pig, so with the rat, vision seems to 

 function mainly for orientation. But the rapidity with which mov- 

 ing objects, especially those which cast a shadow, are seen in- 

 dicates that the guinea pig uses his sense of sight to detect the 

 approach of dangerous objects. 



The noises most quickly reacted to are those indications of 

 danger and other ^signals made by the guinea pigs themselves; 

 and sounds associated with feeding time. 



The most important senses with the guinea pig are the 

 kinesthetic. We can almost say that the guinea pig does the 

 greater part of its remembering in kinesthetic terms. Watson 

 suggests that the memory of a path by young rats is motor. - 

 How prominent a f ature "f rat life motor reactions are has not 

 been discovered by niiy experiments yet carried out. 



Memory Processes — Watson found that memory processes 

 of the white rat are not pre■^ent before the tweltth day (p. 63), 

 but be:ore the twent)-second day they have reached a develop- 

 ment sufficient to civible the solution of problems conditioned 

 chiefly upon activity 43. 73). Psychical maturity is reached at 

 from twenty three to twciity-seven days of age (p. 83). 



The e.xperiments upon which these conclusions are based 

 are : (a) A simple labyrinth used to test the earliest appear- 

 ance of memory of a path to the mother ; (b) other more com 

 plex labyrinths, in the solution of which activity was mainly 

 involved, with memory of the path chosen ; (c) boxes with dif- 

 ferent methods of opening, involving a memory of more com- 

 plex movements than merely those of following a path to food. 



' Animal Education, p. S4. - Loc. cit., p. 8;, foot-note. 



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