548 



THE CENTURY MAGAZINE 



NO. 4. CEBUS FATUELLUS ; FEMALE, 

 EIGHT YEARS OLD 



The "boss" of a large cage full of monkeys and very 

 strong. This animal was so quick in movement that 

 it was impossible to get a clear picture of her. 



only a leap to make and a string to pull to 

 drop them into the cage. 



If one should come fresh from reading 

 some of the current stories which tell of 

 the imitative habits of animals and how 

 "monkeys are the most imitative creatures 

 in the world," to an observation such as I 

 have recorded, he would doubtless be sur- 

 prised. I myself, as hour after hour I 

 watched Jill's indifference to the means of 

 getting food, could hardly believe it credi- 

 ble that she should not perceive the rela- 

 tion between her hunger and the so appa- 

 rent means of satisfying it. Nothing in 

 her behavior, however, led me to believe 

 that she would have learned from Jack if 

 she had seen him do it a thousand times. 



Yet the experiment might not have been 

 quite fair to Jill. Imitative as human 

 beings are, they do not imitate everything 

 they see. Before one could set Jill down 

 as thoroughly stupid, he should present to 

 her the opportunity for imitation under 

 other conditions: he should give her vari- 

 ous other problems and devices. This I 

 was about to do when, on entering my 

 laboratory one day, I found Jack doing 

 not as the fabled hero of childhood, who 

 preceded his beloved mate down the hill 



to destruction, but, alive and well, stand- 

 ing by the prostrate form of Jill. She had 

 died in the night. 



The loss of Jill at this time was a seri- 

 ous handicap. Nothing could be done 

 without getting more monkeys. Another 

 pair was obtained by purchase from New 

 York, but neither of them was in good 

 condition, and only one of them w^as re- 

 tained. The situation was somewhat dis- 

 couraging. My year was nearing an end ; 

 I had obtained but few results. The best 

 animal was dead, and the new one was a 

 poor specimen. Then a bit of good for- 

 tune came along. Through Professor 

 Yerkes, arrangement was made with Dr. 

 Hornaday whereby the investigation could 

 be continued during the summer at the 

 New York Zoological Park, where there 

 were monkeys in abundance. 



In order to make the most of the facili- 

 ties at the park, it was necessary to have 

 the apparatus well prepared beforehand. 

 Accordingly, the next few weeks were 

 spent in devising and constructing a new 

 experiment cage. 



The new cage was slightly smaller than 

 the old one. The frame was made in sec- 

 tions and put together with bolts. The 

 front and one end were covered with gal- 

 vanized mesh wire; the back and the other 

 end were covered with twelve-inch, half- 

 tongued boards, placed vertically. These 

 boards were fastened to the frame by bolts 

 with wing-nuts, and could therefore be 



NO. 4 PUSHING BACK THE BUTTON IN 

 THE BUTTON EXPERIMENT 



