296 INDEX 



Yerkes, R. M., 190, 231, 258, Yoakum, G. S., 259 



intelligence in Carcinus, Yung, E., 190 

 184; in crayfish, 184; in 



frog, 228; in turtles, 230; Zell, T., 259 



variability of behavior in Zeigler, H. E., 114 



dancing mouse, 133, 134 Zurn, F. A., 259 



