Berry, Imitation in White Rats. 343 



No. 7 IMITATING NO. 6 AND NO. 8. 



Time 



45 

 20" 



•5" 

 15" 



Totals 



SUMMARY OF EXPERIMENT IV. 



Average 15.4 • 12.4 6.6 



No. 4 5 5 2 no 



Experiment V . Pulling a Wooden Bar. 



Method. — The apparatus consisted of a wire box with wooden 

 floor. The lengths of the sides were 17 cm., 26 cm., 21 cm., and 

 13 cm.; height, 15 cm. In the small end of the box and about 5 cm. 

 above the floor a door was made that was large enough for a rat 

 to pass through easily. This door, which opened out, was held 

 shut by a small wooden bar, To the end of the bar a string was 

 fastened which passed up over the middle of the box and hung down 

 into it. To the lower end of the string a white, horizontal wooden 



