In the preparation of this little book I have consulted many persons. I am particularly indebted for the reading of the manuscript and for much helpful advice to Mrs. de Schweinitz, to Dr. Louise de Schweinitz, to Mr. and Mrs. C. Reed Cary, Miss Grace Marcus, Mr. Samuel Scoville, Mr. and Mrs. Samuel G. Stem; to Dr. Jessie Taft, director of the Department of Child Study of the Children's Aid Society of Pennsylvania; to Mr. Henry W. Fowler, Associate Curator of the Department of Vertebrate Zoology of the Academy of Natural Sciences in Philadelphia and Mr. William E. Meehan, Superintendent of the Philadelphia Aquarium, who read the sections upon fish; Dr. Frederick H. Allen, Miss Goldie Basch, Dr. Phyllis Blanchard, Miss Almena Dawley, Miss Bertha Reynolds, of the staff of the All-Philadelphia Child Guidance Clinic; Dr. Dan C. Darrow, Instructor in Pediatrics, School of Medicine, Washington University; Miss Elizabeth H. Dexter, Chief Social Worker, Department of Child Guidance, Newark Board of Education; Dr. E. Van Norman Emery, Director of the Los Angeles Child Guidance Clinic; Dr. M. J. Exner, Director of Educational Measures,
