The participating institutions contributing data to this conference together with the name of the responsible investigators are: Memorial Hospital, New York, Dr. Frank E. Adair; Massachusetts Memorial Hospitals, Boston, Dr. T. J. Anglem; Shreveport Charity Hospital, Shreveport, La., Dr. Paul D. Abrahamson; University of Oregon School of Medicine, Portland, Ore., Dr. William Y. Burton; Jewish General Hospital, Montreal, Quebec, Canada, Dr. H. C. Ballon; Swedish Hospital, Seattle, Dr. Franz Buschke; Dalhousie University School of Medicine, Halifax, Nova Scotia, Dr. R. W. Begg; Duval County Tumor Clinic, Jacksonville, Fla., Dr. Frederick H. Bowen; University of Pittsburgh School of Medicine, Pittsburgh, Dr. Joseph Hepp; Cornell University School of Medicine, New York, Dr. William A. Cooper; Chicago Tumor Institute, Chicago, Dr. Max Cutler; University of Wisconsin School of Medicine, Madison, Wis., Dr. A. R. Curreri; Cedars of Lebanon Hospital, Los Angeles, Dr. L. A. Eshman; The British Columbia Cancer Institute, Vancouver, British Columbia, Dr. Maxwell T. Evans; Washington University of St. Louis, Dr. Charles L. Eckert; University of Iowa School of Medicine, Iowa City, Dr. Barry Friedman and Dr. Robert Petersen; San Francisco Hospital, San Francisco, Dr. L. H. Garland; Allegheny General Hospital, Pittsburgh, Dr. Robert C. Grauer; University of Georgia School of Medicine, Augusta, Ga., Dr. Robert Greenblatt; Albany Medical College, Albany, N. Y., Dr. L. W. Gorham; National Cancer Institute, Bethesda, Md., Dr. Roy Hertz; University of Minnesota School of Medicine, Minneapolis, Dr. Robert A. Huseby; Bellevue Hospital, New York, Dr. Ira Kaplan; Ochsner Clinic, New Orleans, Dr. Champ Lyons and Dr. William Parson; Johns Hopkins Hospital, Baltimore, Dr. Edward F. Lewison; Cleveland Clinic, Cleveland, Dr. Perry McCullagh; Vanderbilt University Hospital, Nashville, Tenn., Dr. Barton McSwain; Chattanooga Tumor Clinic, Chattanooga, Tenn., Dr. S. S. Marchbanks; Los Angeles General Hospital, Los Angeles, Dr. Ian Macdonald; Massachusetts General Hospital, Boston, Dr. Ira T. Nathanson; Jefferson Medical College, Philadelphia, Dr. Karl Paschkis; Alameda County Hospital, Oakland, Calif., Dr. Robert J. Parsons; Multnomah County Hospital, Portland, Ore., Dr. Eugene W. Rockey; Duke University Hospital, Durham, N. C., Dr. W. C. Sealy; Cook County Hospital, Chicago, Dr. Joseph Silverstein; Street Clinic, Vicksburg, Miss., Dr. Augustus Street; University of Colorado School of Medicine, Denver, Dr. James Stapleton; Research and Education Hospital, Chicago, Dr. Samuel Taylor, III; University of Kansas School of Medicine, Kansas City, Kan., Dr. Galen M. Tice; M. D. Anderson Hospital, Houston, Texas, Dr. Benjamin Wells; Walter Reed General Hospital, Washington, D. C., Major Keene M. Wallace, M. C.; University of Maryland Hospital, Baltimore, Dr. Grant Ward.