L. J. Spillane and H. P. Leftin, symposium co-chairmen. H. G. McGrath and M. E. Charles, symposium co-chairmen. C.E. Crouthamel and H.L. Recht, symposium chairmen. Raymond Dessy, John Dillard [and] Larry Taylor, symposium co-chairmen. Bernard D. Blaustein, symposium chairman. Roger S. Porter and Julian F. Johnson, symposium chairmen.