The modern physician is aided in his investigations of the human mind and body by numerous assistants who have given special study to the technic of certain fundamental examinations. The psychologist has brought to the medical clinic exact systems of measurement which are of service in determining accurately the extent to which the human mind functions under various conditions. The book by Professor Wallin indicates the methods for determining the limits of the human senses and sensibilities. He provides a consideration of various intelligence tests with criticisms. Two parts of the book are devoted to motor factors and emotional development. An appendix provides an adequate bibliography and a study of the reliability of group intelligence tests. The book is exceedingly informative and provides an accurate picture of the trend of knowledge in its field.