212 'Journal of Comparative Neurology and Psychology. 



the remainder of the summer and almost daily from September 

 to the following May. Subsequently, series of new experiments 

 and repetitions of old ones were given at irregular intervals. Dur- 

 ing each series of experiments, however, the successive tests were 

 made on consecutive days, so that the conditions of hunger and 

 fatigue might be as nearly uniform as possible. The four rac- 

 coons must have been, at the time I secured them, about eight 

 weeks old. Comparisons with the other two, Nos. 5 and 6, whose 

 age I definitely knew, make the above estimate fairly accurate. 



The four raccoons are designated by the numbers i, 2, 3, and 

 4 respectively. The reader should remember that No. 4 alone is 

 a female. When no ambiguity results,! shall use the word "ani- 

 mals" as a synonym for the word raccoons, or, m other connec- 

 tions, for the expression "dogs and cats." This usage, however, 

 does not imply the opinion that different mammals are alike psy- 

 chologically. 



It was my purpose to use tests so similar to those already used 

 in the case of other animals that I might learn by comparisons the 

 place of the raccoon in the scale of mammalian intelligence. This 

 purpose was rather strictly adhered to except in the experiments 

 to test visual discrimination and the presence of visual images. 

 I am not aware that the card-showing device and my method of 

 using it have been employed by other investigators. 



LEARNING TO RELEASE FASTENINGS. 



The method employed in the experiments with fastenings was 

 that used in the laboratory by Thorndike^ in his study of 

 cats and dogs. 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. 



Before proceeding to a description of the fastenings used, and 

 the tabulated records, I may say that I do not believe that my 

 raccoons can fairly be called "victims" of experimental conditions. 

 As long as they continued to suckle, or until August 30, 1905, they 

 were fed from a bottle twice each day until fully satisfied. During 

 August, bits of apple, lumps of sugar and water were added to their 



^ Thorndike, E. L. Animal Intelligence. Psychological Review Monogr. SuppL, yo\. z, no. i^. 



