ABSTRACT
Twenty-one days later, Kimoni (1 year 2 months 17 days) is sitting within the transitional arena formed between the knees of his seated mother, Ganga. After checking with my colleagues at the zoo I supply the chimpanzees with rectangular, plywood boards. Each board is about 28 cm 22 cm and 4 mm thick and has rounded-off corners and bevelled edges. The boards, wrapped in a hessian sack, are left unpainted and I anticipate that upon their smooth, pale, tawny surfaces the chimpanzees might be able to produce lines of greater contrast than the fainter ones they make upon the dark timbers of the Construction and the rough stones around it.
