1 This symposium was held at the Fifty-seventh General Meeting of the Society of American Bacteriologists in Detroit, Michigan, on April 29, 1957. Participants were: W. E. Grundy, Abbott Laboratories, North Chicago, Illinois; C. M. B. Gooding, Best Foods, Incorporated, Bayonne, New Jersey; M. G. de Navarre, Cosmetics Laboratories Division, Beauty Counselors, Grosse Point, Michigan; G. G. Slocum and M. T. Bartram, U. S. Food and Drug Administration, Washington, D. C.; S. S. Block, University of Florida, Experiment Station, Gainesville, Florida.