1. Medicine Branch, National Cancer Institute, and the Laboratory of Experimental Pathology, National Institute of Arthritis and Metabolic Diseases, Bethesda, Maryland 20014.
2. Medicine Branch National Cancer Institute, N.I.H., Bethesda, Md.
3. Section of Histochemistry, Laboratory of Experimental Pathology. National Institute of Arthritis and Metabolic Diseases, N.I.H., Bethesda, Md.