CONTENTS 



12. The Mental Life of Monkeys and Apes: A Study of Ideational Be- 

 havior. By Robert M. Yerkes. Pp. iv+145. $1.50. 



13. A Study of Perseverance Reactions in Primates and Rodents. By G. V. 

 Hamilton. Pp. iv-(-65. $.75. 



14. An Analysis of the Learning Process in the Snail, Physa gyrina Say. 

 By Elizabeth Lockwood Thompson. Pp. iii-(-97. $1.25. 



15. The Effect of Length of Blind Alleys on Maze Learning: An Experi- 

 ment on Twenty-four White Rats. By Joseph Peterson. Pp. iii-(-53. $.75. 



16. An Experimental Studv of Transfer of Response in the White Rat. 

 By Harry H. Wylie. Pp. iii+66. $1.00. 



