552 



STUDIES ON THE MENTAL LIFE OF ANIMALS. 



Fig. 5. — Cat No. 5 in box K. (Thorndi-ke, p. 22. 

 Formation of association.) 



besides, extreineW irregular; after reniaiiiiiig low for some time it 

 sudden!}^ ri.ses at the end of the first series of experiments. The 

 curve carried on the same line of abscissas, showing the results of a 

 new series of attempts after quit(^ a long- interval, shows that associa- 

 tion was still far from being definitely formed; altogether it shows a 



very decided agitation and disorder 

 of mind in the subject. 



The behavior of dogs was in a gen- 

 eral wa}' quite different from that of 

 cats. 



A dog who, when hungry, is shut \x\) in 

 one of these boxes is not nearl}' so vigorous 

 in his struggles to get out as is the young 

 oat. And even after he has many times ex- 

 perienced the pleasure of eating on escape 

 he does not try to get out so hard as a cat, 

 young or old. He paws or bites the bars 

 or screening and tamely tries to squeeze 

 out. He gives up his attempts sooner than 

 the cat if they prove unsuccessful. Fur- 

 thermore, his attention is taken by the food, not the confinement. He wants to get 

 to the food, not out of the box. So, unlike the cat, he confines his efforts to the 

 front of the box. It was also a practical necessity that the dogs should be kept 

 from howling in the evening, and for this reason I could not use as a motive the 

 utter hunger which the cats were made to suffer. In the morning, when the experi- 

 ments were made, the dogs were surely hungry, and no experiment is recorded in 

 which the dog was not in a 

 state to be willing to make 

 a great effort for a bit of 

 meat, but the motive may 

 not have l)een even and 

 equal throughout, as it 

 was witli the cats." 



An examination of 

 the curves for these 

 experiments shows a 

 rapid descent, gener- 

 ally after the second 

 trial, sometimes after 

 the first. Above all. 

 there is recorded in a 

 much less deofree the 



1 — r 



/I 



-Cat No. 'A in box <i. 



(Tborndike, p. 21, Memory.) 



sharp elevations indicating duration. In order to show the contrast, 

 we reproduce the curve relative to cat No. 10, from 4 to S months old, 

 and dog No. 1 placed in two similar boxes, C and C C, closed by a 

 button which had to be broug'ht from a vertical to a horizontal posi- 

 tion in order to open the box. The same remarks apply to the curve 



«Thorndike, pp. 32 and 33, 



