1. Quersin-Thiry, L.: Nutritive requirements of a small plaque mutant of Western Equine Encephalitis virus. Brit. J. exp. Path.42, 511 (1961).
2. Sprecher-Goldberger, S.: A differential effect of Ethidium Chloride on the growth of Arbo A viruses and their small plaque mutants. Acta virol.8, 80 (1964).
3. Kandaswamy, T. S., andJ. F. Henderson: Intracellular differentiation of purine ribonucleotides derived from endogenous sources. Biochim. biophys. Acta (Amst.)61, 86 (1962).
4. Tomchick, R., andH. G. Mandell: Biochemical effects of Ethidium Bromide in micro-organisms. J. gen. Microbiol.36, 225 (1964).
5. Barry, R. D.: The effects of Actinomycin D and ultraviolet irradiation on the production of fowl plague virus. Virology24, 563 (1964).