i66 



THE SOCIAL LIFE OF ANIMALS 



sibility is that a rapidly learning individual becomes 

 a leader in the reaction of the whole group. 



Both of these possibilities were tested experi- 



Qli5* 



OCOMTROL 

 ©PLUS LURE 

 • PLUS LEADER 



TRIAL 



4 5 



A 



Fig. 36. Goldfish learn more readily if accompanied 

 by a trained leader than if there is a fish in the proper 

 position to act as lure. (From Welty.) 



mentally by Dr. Welty, with results which are sum- 

 marized in Figure 36. Three sets of aquaria were 

 established. In the control aquaria all the goldfish, 

 of which there were four in each tank, were fish 

 which had had no previous experience in these ex- 

 periments. These were trained as usual. In another 

 set, an untrained fish was kept in each forward com- 



