forests; the only obvious exception to this rule is the capuchin. They con- 

 cluded that, as with the great apes, a semiterrestrial life and a fairly open 

 habitat in the wild tend toward the evolution of the genetic basis for the 

 ability to perform aimed agonistic throwing, and/or for the actual inclina- 

 tion to do so in captivity. To this generalization the capuchin remains the 

 exception. 



Conversely, however, as Weiner (1963) pointed out. the tool-using abili- 

 ties of a tree-living form such as the capuchin emphasize the point that a 

 bipedal terrestrial mode of life per se is not a necessary preadaptation for 

 the emergence of tool-using activities. He adds, though, that it must have 

 been crucial for the change from tool-using to tool-making. On the basis of 

 observations of higher Primates, we shall later have cause to question this 

 latter view. 



Abundant observations have now accumulated, not only on tool-using 

 by the great apes but even on tool-fabricating. As Le Gros Clark stated in 

 his Raymond Dart Lecture (March 1965), "it has now become clear that 

 they [modern large apes with their small brains] are capable of more elab- 

 orate patterns of behavior than had hitherto been suspected." 



The classical studies by Kohler (1924), Yerkes (194S), and others on 

 chimpanzee behavior have in recent years been supplemented by a host of 

 new studies. The facilities provided by the Witwatersrand University's 

 Uganda Gorilla Research Unit enabled Donisthorpe (1958), Osborn (1963), 

 and others to study the mountain gorilla; the most comprehensive studies 

 on this ape have been made by Schaller (1963). The field studies of Kort- 

 landt (1962) and of Jane Goodall (1963a, 1963b, 1964) have thrown much 

 new light on the behavior of chimpanzees. These field researches have been 

 supplemented by the zoo observations summarized by Kortlandt and Kooij 

 (1963), the Hayes' experiments (1952) with Vike, Mrs. N. Kohts's (1935) ex- 

 periments with her child's gorilla contemporary and playmate, and the 

 exploration by Khroustov (1964) of the highest frontier of implemental ac- 

 tivity in chimpanzees. 



From this wealth of new information emerge certain key observations 

 that bear on tool-using and tool-making or, if one prefers it, tool-modifying 

 activities by the great apes. Tool-using activities— such as agonistic throwing, 

 clubbing, and stabbing— characterize all 3 of the great apes— chimpanzee, 

 gorilla, and orangutan— as Kortlandt and Kooij (1963) have well summarized. 

 Nonagonistic uses by apes include isolated instances of branches being used 

 by gorillas and one orangutan as raking tools for reaching fruit or other 



& "8 



