HABIT FORMATION IN FROGS 327 



degree of perfection of the nervous connections which are in- 

 volved in the acts upon which a habit is estabUshed. Or, to 

 interpret this from the viewpoint of present day ^^erifiable fact, 

 it may be said that the greater the variety of situations which 

 arc successfully met in the natural life of an animal by a special- 

 ized neuro-miiscular mechanism , the more rapid may he the forma- 

 tion of habits involving that mechanism. 



Although this conclusion is clearly supported experimentally 

 only by evidence derived from a comparison of the ra]:>idity 

 of the formation of habits in frogs, much of the work on habit 

 formation in other animals tends to confirm this view. We 

 find the most rapid learning in those cases where experimental 

 apparatus was especially adapted to a " peculiar facility " in 

 muscular action of one sort or another. Thus, to cite an ex- 

 ample, L. W. Cole was led to use problem boxes with fastenings 

 of various sorts to test the intelligence of raccoons, for " the 

 peculiar facility of the raccoon in the use of his forepaws and 

 his tendency to investigate objects by touch suggested at once 

 that he might learn readily to operate simple fastenings." (4, 

 p. 212.) Cole's results seem to show that his raccoons learned 

 more rapidly to operate fastenings than to perform correctly 

 the sensor}^ discrimination tests, although the latter involved 

 fewer muscles and nerves than the former. The reason for the 

 difference is probably that the neuro-muscular mechanism in- 

 volved in undoing fastenings h more highly developed (special- 

 ized) than the mechanisms involved in forming sensory associa- 

 tions; or otherwise expressed, the former mechanism is used daily 

 in the raccoon's active wild life, while that employed in form- 

 ing the sensor}^ associations is seldom employed. 



This explanation of the variation in the rapidity of the forma- 

 tion of habits in the same animal differs essentially from 

 the "prophecy" of Washburn and Bentley: "In general it 

 may be prophesied that the more deep-rooted and essential 

 the instinct appealed to by the ' experience ' to which an 

 animal is subjected, the more rapidly will the animal profit 

 by experience" (10, p. 125). 



I am uncertain of the meaning of " deep-rooted." If the 

 early appearance of an instinct in phylogeny makes it deep- 

 rooted and late appearance makes it less so, the meaning is 

 almost wholly speculative, for we know next to nothing about 



