Modification by Experience 225 



an animal in a sluggish mood may traverse a path very 

 slowly and yet make no errors. 



Kinnaman taught two Macacus rhesus monkeys the Hamp- 

 ton Court maze. That they had an anticipatory idea of the 

 pleasure in store for them at the centre he thinks evidenced 

 by the fact that they would begin to smack their lips audibly 

 on reaching the latter part of their course. Yet for them, as 

 for the rats, one of the most persistent errors lay in taking the 

 wrong turning at the outset (221). 



What is the mental aspect of the process of learning a laby- 

 rinth ? Does it involve that form of memory which consists 

 in the revival of images of past experience ? Or is it simply 

 the gradual formation of a habit of movement, at no stage of 

 which a memory image functions ? In the first place, we may 

 note that no method less calculated to involve images could 

 well be devised. A human being in such a labyrinth as that at 

 Hampton Court, with all his wealth of image- forming and 

 controlling power, is at a loss to make use of it for his guid- 

 ance. Secondly, there are various phenomena displayed in 

 the experiments which tell against the image theory. For 

 one thing, the slowness of the learning process in the simple 

 labyrinths indicates that memory in this sense is not concerned. 

 When an animal has the choice between two passages only, 

 if it possessed the power of recalling, in any terms whatever, 

 a memory image of its previous experience, surely thirty or 

 forty trials would not be required before the right path was 

 taken at once. Again, the nature of the errors made in some 

 cases suggests that memory images are not present. For in- 

 stance, when Small's two rats had learned the complicated 

 labyrinth almost perfectly, the one error in which they both 

 persisted lay in taking the wrong turn at the entrance. Now 

 this, it is safe to say, would be the very first error that a being 

 which guided itself by images would eliminate. It might be 

 Q 



