AN ANALYSIS OF THE LEARNING PROCESS IN THE SNAIL 87 



Observational work on mollusks has-been reported, but little 

 experimental work has been done on this group of animals, 

 none along the lines of the present work. Kollmann (1877) 

 attributed " consciousness " to Octopus vulgaris, basing his con- 

 clusions, however, on observation rather than experiment. In 

 his analysis of this report, Schneider (1909) explains the behavior 

 observed as reflexive, not " conscious," and hence typical of 

 any of the lower animals. Pieron (1909) concludes that the 

 octopus is capable of " learning," and although Kafka (1914) 

 reports this work he does not analyze it. Modifiability of 

 behavior then, may be attributed to members of the Cephalopod 

 group. Pieron (1909), (1911) experimented on the waning of 

 the effect of stimuli inducing reflexive action in Limnaea stagnalis 

 and Littorina, which he terms memory. Associative memory 

 as observed in the present work was believed to be an added 

 proof of learning, but no attempt was made to determine its 

 exact duration nor the way in which it developed. The work 

 of Pieron is here of interest only in that it deals with so-called 

 memory (adaptation) in closely related forms. 



III. CONCLUSIONS 



1. The present work on the snail, Physa gyrina Say, gives 

 much evidence of capacity for adaptation — the getting-used-to- 

 the-stimulus. This is quite apart from evidence for fatigue 

 which appears in some places. 



2. In addition to adaptation its behavior is modifiable by 

 experience in another way. As the result of prolonged training 

 with two simultaneous stimuli it is found to have acquired a 

 response to one of these stimuli which it did not give before. 

 It has formed an association between the two stimuli. 



3. This definite acquired response is retained for four days 

 beyond the completion of the training (memory). 



4. When put through a long series of tests with the simplest 

 form of labyrinth, under controlled conditions it shows no 

 capacity to solve the labyrinth. 



5. On a similar labyrinth it gives evidence of the capacity 

 to form associations. 



6. The capacity to form associations does not then suffice 

 for the solution of the simplest labyrinth, that is, " selective " 

 ability is apparently lacking. 



