========+===========+==============+==============+==============+==============+==============+==============+==============+==============+==============+==============+===+===+===+===+======== [Footnote *: Aided by experimenter.] The evidence suggests that in this young orang utan ideational learning tended to replace the simpler mode of problem solution by trial and error. Seemingly incapable of solving his problems by the lower grade process, he strove persistently, and often vainly, to gain insight. He used ideas ineffectively. Animals far lower in intelligence (e.g., the pig), surpass him in ability to solve these relational problems because they use the method of elimination by trial consistently and effectively. Julius, in these experiments, made a poor showing because his substitute for trial and error is only slightly developed. Would he have succeeded better with the same problems if mentally mature? There are many important features of the results which, for lack of space, have not been indicated or discussed. They can be developed from later comparative studies of the data, for in the tables appear all of the essential facts of response apart from those mentioned in the text. IV RESULTS OF SUPPLEMENTARY TESTS OF IDEATIONAL BEHAVIOR 1. Julius, _Pongo pygmaeus_ _Box Stacking Experiment_ In addition to the multiple-choice experiments which have been described in detail in the previous section, it was possible to conduct certain less systematic tests of ideational behavior in the monkeys and the orang utan. From the technical standpoint these tests were relatively unsatisfactory because only inexactly describable. But their results are in many respects more interesting, if not also more important, in the light which they throw on ideation than are those previously presented. First, in order of time, comes a test which may be designated as the box stacking experiment. The method will now be described in connection with an account of the behavior of Julius as contrasted with that of a child of three years and four months of age.