Further observations on the genetic transfer of drug resistance in Eimeria maxima

Experiments are described which support the view that, in Eimeria maxima , drug resistance factors are transferred at zygote formation. The phenomenon occurred between infections which were initiated by the inoculation of merozoites. It also took place between variants of the same, but not between different species. Transference of drug resistance wsa not affected by the treatment of the chicks with acriflavine.