Literary Notices. 34 1 



According to the author, " Perception of the essential relations, if present at all, is 

 dull and stupid in the last degree" (p. 468). ^'et "there is an evident ability to 

 respond to small differences in complex relations. How far the perception of such 

 relations really enters is, however, at present in doubt" (p. 477). Practical denial 

 is weakened to doubt within a few pages, because of the contrast between what one 

 raccoon did and what they all did. However, the study of the perception o( rela- 

 tions in animals is a new •field. It is enough for most workers at present if they 

 can prove the perception of an easily discriminated object and say with certainty 

 whether it is a visual, olfactory, or tactile perception. Perhaps, however, Mr. Davis 

 means that the raccoons did not perceive the fastenings, though they responded to 

 small differences in them, for his confirmation of Thorndike commits hmi 

 to the latter's statement (p. 80) that "the loop is to the cat what the ocean is to a 

 man when thrown into it, when half asleep." 



This apparent conflict between conclusions is evident throughout the paper and 

 it seems to be due to the old discrepancy between isolated observations and the 

 final and impersonal result of systematic records, a conflict which Thorndike tried 

 hard to terminate. 



In working the combination locks the animals learned "order" and "amount 

 of effort" at somewhat different rates. "The table seems to show that the memory 

 of the order is more readily perfected than that of the muscular ■ adjustment 

 required for each particular locking device" (p. 469). Does this mean two types 

 of "memory," as is indicated by this quotation, or merely two rates of habit form- 

 ing, or a type of memory and a case of habit forming, which we should expect to 

 develop at two different rates ? Varying the locking devices would doubtless 

 have explained the phenomenon or analyzed it for us. If it is due to mere 'lefect 

 in method, varying the device would have ehmmated it. So the observation seems 

 significant for future tests. If we can find two widely divergent rates, we may find 

 a distinction between habit and association. Kinnaman, who tested monkeys 

 with combinations very similar to those used by Mr. Davis, does not call our atten- 

 tion to any difference in the rate of learning "order" and "amount of effort." 

 This adds interest to Mr. Davis's observation. 



An e.xcellent table is given of the first forty trials of raccoon No. i with the single 

 fastenings and groups. The generalized curves are too greatly reduced to be of 

 much value. A curve for Kinnaman's monkey's is given, but Kinnaman counted 

 the entire time "no matter whether the monkey was before or behind the box, 

 whether prancing around it or jumping up and down on top of it, so long as he was 

 trying to open it. Some of these efforts were in nowise directed toward the latch" 

 (Kinnaman, p. 115). Davis, on the contrary recorded the time during which the 

 animal was in contact with the locking device (Davis, p. 465). Surely this differ- 

 ence must be taken into account in valuing his conclusions that the raccoons show 

 a nearly equal facility with Kinnaman's monkeys in learning to undo fastenings, 

 and that "the monkeys would seem to be a little less clever at the start" (p. 476). 

 Cole had previously concluded that "in the rapidity with which it forms associa- 

 tions the raccoon seems to stand almost midway between the monkey and the cat, 

 as shown by the numerical records for those animals. In the complexity of the 

 associations it is able to form it stands nearer the monkey" (Cole, p. 261). His 

 method of timing agreed with Kinnaman's and with Thorndike's, though his 

 animals were young and exhibited "play trials." Mr. Davis's method of timing 



