1. See, for example,I. Berenblum, Cancer Res.1, 807 (1941); Arch. Path.14, 471 (1954).
2. P. Shubik andA. C. Ritchie, Cancer Res.13, 45 (1953).
3. R. Daneel andN. Wissenfels, Naturwiss.42, 128 (1955).
4. B. Schär andR. Meier, Exper.12, 30 (1950).
5. R. Meier, P. A. Desaulles, andB. Schär, Arch. exp. Path. Pharm.224, 104 (1955).