31 JANUARY 1925, Page 20

Professor W. Kohler spent many years observing the be- haviour

of anthropoid apes ; setting them small intelligence tests ; and noting down their conduct in affection, excitement, anger, and other emotion states. His experiments are recorded in The Mentality of Apes (Kegan Paul), -translated by Ella Winter, B.Sc. There is a great deal of quite exciting infor- mation on the progress in the use of tools, and there are incidental comparisons of the mental processes of apes and men.