92 Studies in Animal Behavior 



ToRREY, H. B. (i) The method of trial and 

 the tropism hypothesis. Science N. S. 26, 313, 

 1907; (2) Trials and tropisms, 1. c. 37, 873, 1913- 



Washburn, M. F. The animal mind, N. Y., 



1909- ^ ;. ■[[J'.u 



