From the Department of Obstetrics and Gynecology (L. J. G. and W. R. L.) and the Department of Biostatistics (H. M.), Jefferson Medical College, Philadelphia, Pa.

The authors wish to thank the following individuals, all associated with the Board of Education, Philadelphia, Pa.: Mr. Grover W. Mueller, Director of the Division of Physical and Health Education; Doctor Ruth H. Weaver, Medical Director; Miss Josephine Christaldi, Supervisor of Remedial Physical Education; Miss Helen Conkling, Physical Education Teacher; Miss Gertrude Safer, and Mrs. Alexander Blank.