This is the second volume in what promises to be a valuable series for those interested in the basic problems of cancer research. Little of the material is of primary interest to the clinician, with the possible exception of the sections on ionizing radiations, clinical use of nitrogen mustards, and the experimental chemotherapy of cancer. Almost the entire text is devoted to problems related to carcinogenesis under experimental conditions. The section on the reactions of carcinogens with macromolecules is particularly interesting, especially in view of the use of various polymerized plastics in surgery. The experimental findings of tumor production on implantation of films of both commercial and highly purified cellophane, polyethylene, polytetrafluoroethylene (Teflon), polystyrene, nylon, Dacron, Silastic, and polyvinyl chloride are important to surgeons. Peculiarly enough, when these substances are used in the form of perforated films or woven textiles, they are much less active. It has been postulated that