1. Ackermann, W. W.,F. E. Payne, andH. Kurtz: Concerning the cytopathogenic effect of poliovirus—evidence for an extraviral toxin. J. Immunol.81, 1 (1958).
2. Appleyard, G., J. C. N. Westwood, andH. T. Zwartouw: The toxic effect of rabbitpox virus in tissue culture. Virology18, 159 (1962).
3. Bernkopf, H., M. Nishmi, andA. Rosi: Effect of active and inactive vaccinia virus preparations on human amnion cell cultures. J. Immunol.83, 635 (1959).
4. Brown, A., S. A. Mayyasi, andJ. E. Officer: The “toxic” activity of vaccinia virus in tissue culture. J. infect. Dis.104, 193 (1959).
5. Burnet, F. M.: Principles of Animal Virology, 2nd Ed. New York: Academic Press, Inc. 1960.