1. Acknowledgments. We are grateful to Prof. J. Walker and the staff of the Radiation Centre and Nuffield Cyclotron, Department of Physics, Birmingham University, England, and for the cooperation of Dr A.T.M. Vaughan, Department of Immunology, The Medical School, Birmingham. We are also grateful to Dr L. M. Franks of the Imperial Cancer Research Fund Laboratories, Lincoln's Inn Fields, London, for the supply of the original mouse tumors. We also thank Mr L.F.H. Beard and Mr M. Johns and the staff of the Department of Medical Illustration and Photography, Addenbrooke's Hospital, Hills Road, Cambridge.
2. Mitchell, J.S., Brown, I., and Carpenter, R.N., Experientia39 (1983) 337.
3. Mitchell, J.S., Brown, I., and Carpenter, R.N., in: Essays on Human Alkaline Phosphatase. Eds T. Stigbrand and W.H. Fishman. Alan R. Liss, Inc., New York 1984.
4. Mitchell, J.S., Brown, I., and Carpenter, R.N., Br. J. Radiol., prepared for publication (1984).
5. Brown, I., Carpenter, R.N., and Mitchell, J.S., Br. J. Radiol., prepared for publication (1984).