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CONTRIBUTORS
JOHN D. SPIKES, Department of Experimental Biology, University of
Utah, Salt Lake City, Utah
HELEN A. STAFFORD, Biology Department, Reed College, Vortland, Oregon
P. K. STUMPF, Department of Biochemistry, University of California,
Davis, California
KENNETH V. THIMANN, Harvard Biological Laboratories,
Cambridge,
Massachusetts
GEORGE WALD, Biological Laboratories of Harvard University, Cambridge, Massachusetts
H. R. WHITELEY, Department of Microbiology, University of Washington, Seattle, Washington