92 E. L. THORNDIKE. 



combination. Cats 2, 3, 4, had had some experience of D, 

 which worked by a string something like the string part of K. 

 The string in K was, however, quite differently situated and re- 

 quired an altogether different movement to pull it. Since fur- 

 ther No. 2, who had had ten times as much experience in D as 

 3 or 4, succeeded no better with the string element of K than 

 they, it is probable that the experience did not help very much. 

 All else in all these compound associations was new. At the 

 same time the history of these animals' dealings with these boxes 

 would not fairly represent that of animals without general ex- 

 perience of clawing at all sorts of loose or shaky things in the 

 inside of a box. These cats had learned to claw at all sorts of 

 things. The time curves were taken as in the formation of the 

 other associations, and, in addition, the oi^der in which the ani- 

 mal did the several things required was recorded in every trial. 



In the case of all the curves, except the latter part of 3 in G, 

 one notices a very gradual slope and an excessive irregularity 

 in the curve throughout. Within the limits of the trials given 

 the animals are unable to form a perfect association and what 

 advancement they make is very slow. The case of 3 in G is 

 not an exception to this, but a proof of it. For 3 succeeded in 

 making a perfect association, by accidentally hitting on a way 

 to turn the compound association into a simple one. He hap- 

 pened one time to paw down the thumb-piece at the same time 

 that his other fore-limb, with which he was holding on between 

 the door and the top of the box, was pressing against the door. 

 This giving him success he repeated it in later trials and in a 

 short time had it fixed as an element in a perfect association. 

 The marked change in his curve from an irregular and gradual 

 slope at such a height as displayed a very imperfect association 

 to a constant and very slight height shows precisely the change 

 from a compound to a simple association. 



Compound associations are formed slowly and not at all well. 

 Further observation shows that they were really not formed at 

 all. For the animals did not, except 3 in K for a certain period, 

 do the several things in a constant order, nor did they do them 

 only once apiece. On the contrary, an animal would pull the 

 string several times after the bolt had gone up with its custom- 



