are to be found in Categories, or than in others. Preliminary comparisons have already suggested interesting contrasts between chimpanzee and bonobo. If we scrutinize the minute details of the behavioral patterns of these sibling species, we may find many more differences between them. As less is known of the behavior of the two chimpanzee subspecies of central Africa, it is presently impossible to delineate Category above. However, recent progress at Goualougo is encouraging. Also, an increasing amount of information has emerged on West African chimpanzees, especially those of the Ta Forest, Bossou, and Fongoli, in addition to older data from Kanka Sili and Assirik, we can tentatively regard the common patterns of eastern and western chimpanzees as candidates for behavior common to the species Pan troglodytes. Since most