262 EDWARD J. KEMPF, M. D. 



placed himself in many awkward positions. Extended his hind 

 legs and body in a vertical position, holding to the wire netting 

 with his hind feet. He turned around, finally standing upside 

 down in a vertical position with his head near the aperture. 

 He succeeded in scratching the bottom of the box but could 

 not reach the food. Then he seemed to lose his balance and 

 fall over on his side. This accidental" position was correct for 

 reaching the food. He pulled out the piece of bread. He ate 

 the bread. A peach was lying in the box. He tried repeatedly 

 to reach it but could not and did not assume the proper posi- 

 tion again. F grabbed the peach. Handful of peanuts were 

 dropped into the box. F grabbed most of them. 



Now D tried all types of movements, squirming into one 

 position after another in a most useless and fruitless manner. 

 Twice his body happened to get into the proper position to easily 

 reach the food but each time he changed his reaching hand 

 from the one beside the aperture to the one on the opposite 

 side of his body. He continued to try, raised his body and hind 

 legs into the upside-down vertical position, holding on to the 

 screen with his hind feet; then reached into the aperture with 

 the off side hand and pressed his face into the aperture. His 

 hand touched the nuts and he extracted four despite the awk- 

 ward position of his hand. He then left the box to eat. Then 

 he returned to get more nuts and seemed to be unable to reach 

 them or resume his old position. He shook the box fruitlessly. 



The next day the observations were repeated and D seemed 

 to learn all over again. He went through a series of trials 

 and errors and finally, more quickly than the day before, assumed 

 his unique, awkward method. This method he developed until 

 he became fairly dexterous. 



He places his right hand on the wires just above the cross 

 bar to steady himself and raises his body and hind legs above 

 his head and shoulders, placing himself in a more or less vertical 

 position. The abdomen and chest are pressed against the wires. 

 He extends the left hand, which is on the opposite side of the 

 body, through the aperture, this allows the arm to remain nearly 

 straight, and scrapes the back of the fingers over the box floor 

 until he happens to touch a nut. He required 5, 3, 3, 4, 10, 10 

 and 156 seconds for each trial to extract a nut. 



