342 'Journal of Comparative Neurology and Psychology. 



to rule. The victor, however, often delights in continuing punish- 

 ment which the vanquished receives with howls and shrieks of fear. 

 The noise made by the victim is out of all proportion to the injury 

 inflicted. A slajD, a theft of banana, or even a threat often arouses 

 piercing shrieks. 



No. 6 and No. 4 were together one day in a small cage. It was 

 about feeding time and both wanted to be at the wire front. No. 

 6 was in the way of No. 4 and she sla2:)ped him with the palm of 

 her hand. He retreated and doubled uj) in his characteristic fashion, 

 moving his body up and down and yelling loudly. Any movement 

 of No. 4, even so much as the turn of her head toward him, served 

 to release another volume of shrieks. This continued for several 

 minutes with no further demonstration on the part of No. 4. 



On another day. No. 4 was sitting on a brace in the experiment 

 cage with her hands on the wire. Without allowing her to see 

 me move, I touched my finger to the back of her index finger. As 

 if struck by an electric current she leaped to the floor and began 

 to yell vehemently and continued to do so for some time. 



I am informed by Dr. Hornaday that the Cebus monkeys which 

 are marketed in this country are obtained when quite young. The 

 offspring rides about on the mother's back and hunters shoot the 

 mother, who falls to the ground with the young still clinging to 

 her. The small animal is then caught and kept in captivity until 

 the keeper desires to ship it to market. This makes it next to 

 impossible for any one who buys these monkey's of dealers to know 

 much about their previous experience. 



In a study such as this, however, it is desirable to know all that 

 can be known of each animal's normal activities, so at the risk of 

 multiplying words, I shall give a brief account of each animal used. 



(h) Characteristics of hidividual Animals. — No. 1, Cebus lunatus, 

 female, and No. 2, Cebus lunatus, male, Avere obtained from an 

 animal dealer in New York City. When they came to the Har- 

 vard Psychological Laboratory in November, 1907, they were ap- 

 parently about three years old and were in excellent physical condi- 

 tion. 



No. 1 made herself at home from the start and on the third day 



