Dr. Holló Ferenc szerk.: Parasitologia Hungarica 3. (Budapest, 1970)

Since the developmental stages of Eimeriae differ in loth morphological and biological properties, these features are regarded specific characteristics for species differentiation. Albeit the details of exogenic development are well known with most eimerian parasites, information on the endogenic cycle is often scanty. In fact, studies of endogenic cycle have been centred primarily on the coccidia of gallinaceous birds important from economical point of view,and little has been published in this context on the coccidian parasites of other host species. The strict host specificity and organ specificity, often even with distinct site preference are species characteristics of Eimeriae

. Certain species (

Eimeria mitis

, E.mivati

, E.mayurai

, E.duodenalis

, E

.grenieri

, etc.) settle chiefly in the duodenum, others (

E.maxima

, E.meleagridis

, etc.) in posterior segments of the intestine and others again prefer the coecum (

E.tenella

, E. adenoeides

, etc.) or even the rectum and cloacal mucosa (

E.bru- netti

). The life cycle of E.nectarix is particular. The schizogony of this coccidium proceeds in the small intestines of chickens,the telomerozoites released by the schizonts pass down the coecum and gametes develop within the caecal epithelial cells

. A further common feature of Eimeriae is that they develop intracellularly; only some motile developmental stages occur temporarily outside the host cell. Such motile stages are the excysted sporozoites, first, second,etc. generations of merozoites as well as the microgametes

, which search the macrogametes by active movement after release from the microgametocyte

. Up to recently, it was almost dogmatically accepted that Eime riae are epithelial parasites, however, light microscopic and, particularly, electronmicroscopic studies have increasingly revealed the presence of endogenous stages also in cells of mesenchymal origin.It remains to be clarified whether these cells