reach the bait. Then, to get at the bait, the chimpanzee was faced with a 

 series of situations of increasing complexity that made increasing demands 

 of tool-using and tool-making for their solution. The experiments may be 

 summarized as follows: 



1. A straight smooth rod was provided, that is, an implement suitable 

 for the action required. The chimpanzee had no difficulty in pushing out 

 the bait. 



2. The same rod was provided, but with a crosspiece at one end. The 

 chimpanzee did not immediately find the correct solution. The idea that 

 the stick had to be inserted into the tube had, apparently, fixed itself in 

 the animal's mind— but no more than that, for it at first grasped the stick 

 by the free end and attempted unsuccessfully to insert the end with the 

 crosspiece into the metal tube. Later, it tried the other end with success. In 

 both these preliminary experiments, success could be achieved without any 

 modification of the tool. 



3. In the third stage, some modification of the tool was necessary. The 

 rod was fitted with 2 crosspieces, one at either end. After unsuccessful at- 

 tempts to use the rod directly as an implement, the animal broke off one 

 crosspiece: however, the earlier associations were not sufficiently fixed in 

 its mind, and it then attempted to thrust into the tube the other end with 

 intact crosspiece. Only after the failure of such attempts did the animal find 

 the correct way to use the rod. It seems that the connection had not yet 

 been established between the changes that it wrought on the implement and 

 the possibility of using it as an implement. To quote Khroustov: 



The destructive actions of the anthropoid on the one hand and its attempts to 

 perform iniplemental action on the other remained separate operations not united 

 into a chain. Only by establishing the connection between these operations and 

 their organization into a single chain do the destructive actions receive definite 

 direction, turning into a directed treatment of the implement and thus forming 

 a link in the whole chain of activity. [Ibid., p. 505] 



Further experiments led the chimpanzee to hit upon the connection 

 that had escaped it before. It was given a tree branch with a side shoot: it 

 broke off the shoot and so gained the bait with the branch. When it was 

 again given the rod with 2 crosspieces, after some hesitation and several 

 abortive trial-and-error actions, the connection seems suddenly to have been 

 established. The chimpanzee grasped the rod, immediately broke off both 

 crosspieces and the string binding them, and then used the free rod as an 

 implement. 



121 g 



