Haggerty, Imitation in Monkeys. 351 



On the other hand, if the prohlenis arc adjusted in a small box, the 

 animal is cramped and often frightened. In order to minimize these 

 difficulties I built an experiment cage (fig. 1) which was 182 cm. 

 high, 124 cm. broad and 92 cm. deep. It was large enough to 

 allow considerable freedom to the animal and yet not so large but 

 that the monkey was kept near the problem all the time. The top, 

 the floor, the back and one end of the cage were made of rough pine 

 boards. In these board parts of the cage were adjusted several 

 mechanisms. The problem for the monkey was to manipulate one 

 or another mechanical device. The front of the cage and one end 

 were covered with half -inch mesh wire which made possible a view 

 of the entire interior. At the iM^ttom of the front was a slide door 

 through which the animals were introduced into the cage. 



This cage was used in all the preliminary experiments and for 

 the first complete set of imitation tests. In the light of knowledge 

 gained in its use, a new and improved cage was built. Hereafter, 

 these two cages will be designated as the old cage and the new cage 

 respectively. 



The new cage (fig. 2) was used in all the exj^eriments made at 

 the Park. It was made of clear white pine lumber, was built in 

 sections and put together with bolts. The frame was in four parts, 

 of material 41/^ cm. square. The front frame, a, h, c, d, and the 

 back frame, e, f, g, h, were each 118 cm. by 180 cm. The end 

 frames, i, g, Jc, I, and m, n, 0, p, were each 85 cm. by 180 cm. 

 When these four parts were bolted together they made a cubical 

 frame 85 cm. by 118 cm. by 180 cm. Across the front, half way 

 up was a brace, q, of the frame material. The end of the brace, 

 X, was a favorite place for the animals to perch. The front and 

 one end of the frame were covered with galvanized woven wire of 

 one inch mesh. The back of the cage was covered with four 

 boards. A, B, C , and D, 29 cm. wide and 2 cm. thick, placed verti- 

 cally and fastened to the top and l)ottom of the frame by bolts 

 with wing nuts, W. The remaining end of the frame was similarly 

 covered by three boards, one of which, E, was fastened as those on 

 the back, and two of which, F and G, were made into a door hinged 

 at li.^ The top of the cage consisted of three boards II, I, and /;, 29 



