stage of its functional preparation, which is a necessary prerequisite for the 

 transition to the primary forms of labor, as an activity peculiar to human 

 beings" (ibid., p. 507). 



8. Finally, once the chimpanzee had mastered the full manufacturing of 

 the implement under the conditions just outlined, further experiments were 

 devised to find the limits of its experimental activity. A similar series of ob- 

 jects was given to the animal and it had to make the same implement. Only 

 this time the rods and discs were of a tough wood, which the animal was 

 unable to break with its natural equipment of hands, feet, and teeth. A 

 stone implement in the form of a hand ax was provided to assist the chim- 

 panzee in breaking the tough wood. Numerous and persistent attempts were 

 made by the chimpanzee to break the wood, but in none did he try to 

 treat the unyielding material with the stone implement, or with anything 

 other than his natural or bodily equipment. For the first time in the whole 

 series of experiments, an attempt was made by demonstration to teach the 

 chimpanzee what he needed to do, namely to use the stone tool. Even then, 

 the chimpanzee made no attempt to copy the actions of the experimenter and 

 use the stone implement, despite its most strenuous and prolonged efforts 

 after the demonstration to overcome the resistance of the material. It seems 

 that the decisive step of using a tool to make a tool was impossible for the 

 ape under these experimental conditions. 



Whether an ape could overcome this barrier under other conditions can 

 be determined only by further experiment. Meantime, Khroustov concludes 

 that: 



The limited scope of using the natural organs as means for making adaptational 

 changes of implements tied down the development of the implement al activity of 

 man's ancestors to definite boundaries and possibilities. When these were ex- 

 hausted, the immediate forebears of man by force of necessity were brought to the 

 threshold of the frontier, on the surmounting of which depended their survival. 

 [Ibid., p. 508] 



That is, they needed to learn to use objects as a means for transforming 

 materials into implements— and so they crossed the frontier itself: "the crea- 

 tion of artificial means for producing implements" (ibid., p. 508). 



Thus, using a somewhat narrower definition of human cultural behavior 

 than that used by Kortlandt and Kooij, Khroustov draws a line between the 

 apes and man and aligns the australopithecines in this regard with the apes. 



It is clear that the level of implemental activity that the living great 

 apes can attain in the wild, in captivity, and under experimental conditions 



123 5£ 



