Published online by Cambridge University Press: 06 April 2009
In dibacterial cultures of E. invadens the size of the cysts was significantly influenced by different species of concomitant bacteria, and by the composition of the media. These factors appear to influence cyst size as a result of their effect on the growth rate of the amoebae; a higher multiplication rate was associated with a decrease in the size of the cysts.
I wish to thank Dr A. Bishop for criticizing the manuscript, and Mr W. McConnachie, jun., for assistance with the statistical methods. The work has been financed by the Medical Research Council.