18 TRAITS OF YOUNG CHIMPANZEES 



physique when he came to me and has so continued. Al- 

 though he had every possible opportunity to contract tuber- 

 culosis he seemingly escaped. At any rate his physical condi- 

 tion appears to be excellent. He is extremely active and to 

 the tuberculin test (intra-cutaneous) his reaction is com- 

 pletely negative.^ 



In addition to observmg the varied behavior and environ- 

 mental relations of the animals in order to familiarize myself 

 with their characteristics, it was arranged to give special 

 and systematic attention to evidences of insight in their 

 adaptive responses, to innate reactive equipment, and to 

 vocal expressions. Considerable progress has been made 

 in each of these several directions. 



Since this report is merely a chapter from the life history of 

 a pair of young chimpanzees, it is scarcely appropriate to offer 

 a historical summary of studies of chimpanzee behavior. 

 Such a summary is in course of preparation, but it may more 

 properly find place elsewhere than here. I may mention 

 certain conspicuously important contributions to our 

 knowledge of chimpanzee behavior. Most notable of all 

 are the reports of investigations at the Canary Island anthro- 

 poid station. In the bibliography which concludes this 

 report will be found several publications from and about 

 that station. Of pecuhar interest and value is the monograph 

 by Koehler entitled " Intelhgenzpruf ungen an Menschen- 

 affen." 



It is pertinent to remark that Koehler (now Professor of 

 Psychology in the University of Berlin) and the writer, in 

 touch since 1914, have been able to assist one another 



^ For administration of this test I desire to make grateful acknowl- 

 edgment to Major A. P. Kitchens, Medical Corps, United States Army, 

 and Captain R. A. Kelser, Veterinary Corps, United States Army. 



