The fate of the sporozoites of Eimeria acervulina, Eimeria maxima and Eimeria mivati in the caeca of the fowl

The sporozoites of Eimeria acervulina and E. maxima when injected into the caeca of chickens fail to produce infections. Sporozoites of E. mivati injected into the caeca invade the walls and the life-cycle is completed. These observations are discussed in their relation to the fate of sporozoites injected into the allantois of chick embryos. The possible use of these techniques in confirming the identity of a species is discussed. We wish to thank Mr B. J. Millard for technical assistance with the preparation of the sporozoites.