THE CHICAGO EXPERIMENTS WITH RACCOONS 163 



of movement — was constant from trial to trial, whereas a selective 

 response must needs have an alternating cue". (Italics mine). 



I know of no way in which light can stimulate these animals 

 except visually. And when the animals were permitted to react, 

 it was by means of a function representative (at least partly) 

 of the lighted box. One would think that the simplest escape 

 from this dilemma would be by means of a visual image. But 

 no, it is visual in source or cause, yet imageless in content. We 

 have often been led to believe that sensation gives a rather 

 fundamental content to thought. Perhaps we may now teach 

 that Helen Keller, for example, has both the content of visual 

 experience as well as a knowledge of its relations. Loeb 6 has 

 recently given evidence to show that a retinal image produces 

 a brain image, which corresponds with the former point for 

 point. "Diese Tatsachen enthalten aber, wie mir scheint, auch 

 den Nachweiss, dass in Gehirn ein Bild der gesehenen Gegen- 

 staende entsehen muss" (p. 1016). By Hunter's hypothesis 

 all of this image forming apparatus is rather useless, for no mental 

 image arises in the raccoon, nor perhaps in the youngest child, 

 under the conditions of the experiment. 



Doubtless it will occur to the reader of Hunter's paper that 

 this explanation of the raccoons' behavior, by means of imageless 

 thought, was in no way suggested to him by his experiments 

 and seems to be a rather foreign addition to his thesis, forced 

 upon him by the milieu or suggested by current discussions 

 of the topic in human psychology. In order to use the concept 

 to account for the results of his experiments he must make the 

 claim (p. 77) that imageless thought is genetically prior to 

 thoughts with images, and he must dismiss the opposite teaching 

 as having "no factual basis" but seeming to be "the result of 

 prejudice or of temperamental leaning." Then the point of 

 origin of imageless thought is placed "at least as low as the 

 raccoon" (p. 77). All this seems a trifle complex to me but the 

 actual advance made is, now that the old explanation has been 

 given up, that the reader may choose what hypothesis he will 

 under the law of parsimony. 



Doubtless psychologists will be more interested in Hunter's 

 immediate explanation than in his final one, which I have already 



6 Loeb, J. Die Bedeutung der Anpassung der Fische an den Untergrund fuer 

 die Auffassung des Mechanismus des Sehens. Zeit.f. Physiol., 1911, 25, 1015-1017. 



