4 8 4 



POPULAR SCIENCE MONTHLY. 



perpendiculars, we draw only a line joining their tops. Tig. 4 

 shows, then, the curve for the real history, and Fig. 5 shows the 

 abrupt descent, due to a rational comprehension of the situation. 

 I kept an accurate record of the time, in seconds, taken in every trial 



by every cat in every 

 box, and in them all 

 there appears no evi- 

 dence for the presence 

 of even the little rea- 

 soning that "what 'let 

 me out of this box three 

 seconds ago will let me 



FlQ 4 out now." Surely, if 



an animal could rea- 

 son he would, after ten or eleven accidental successes, think what 

 he had been doing, and at the eleventh or twelfth trial would at once 

 perform the act. But no ! The slope of the curves, as one may see 

 in the specimens shown in Fig. 6, is always gradual. So, in saying 

 that the behavior of the animals throughout the experiments gave 

 no sign of the presence of reasoning I am not giving a personal 

 opinion, but the impartial evidence of an unprejudiced watch. The 

 curves given in Fig. 6 are for cats learning to escape from the box 

 already described, whose door was held by a wooden button on the 

 inside. 



Some one may object that, true as all this may be, the intelli- 

 gent acts reported of animals are in many cases such as could not 

 have happened in this way by accident. These anecdotes of ap- 

 parent comprehension and inference are really the only argument 

 which the believers in reason have presented. Its whole substance 

 vanishes if, as a matter of fact, ani- 

 mals can do these supposed intelligent 

 acts in the course of instinctive strug- 

 gling. They certainly can and do. I 

 purposely chose, for experiments, two 

 of the most intelligent performances 

 described by Romanes in his Animal 

 Intelligence namely, the act of open- 

 ing a door by depressing the thumb- 

 piece of an ordinary thumb-latch and 



the opening of a window by turning a swivel (see pp. 420422 and 

 p. 425 of Animal Intelligence, by G. J. Romanes). Here I may 

 quote from the detailed report of my experiments (Monograph Sup- 

 plement to the Psychological Review, No. 8): 



" G was a box 29 X 20 X 22|, with a door 29 X 12 hinged 



FIG. 5. 



