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

vestigations have shown the walls of E.tenella (McLAREN, 1969, etc.) and E.megalostomata oocysts (ORMSBEE,1939 ) to he trilamellar. The concept that the oocysts of G-allif

ormes had unilamellar walls was apparently erroneous. On the sphaerical oocysts the micropyle is as a rule invisible. The more or less conspicuous micropyle of the oval and elliptic oocysts may be focussed by light microscope; sometimes the structural change of the cyst wall at a given site is the only indication of the presence of a micropyle. With all Eimeriae of gallinaceous birds, sporogony takes place in the external world. The sporont of the freshly excreted oocyst soon shrinks to a round body.Its division to sporoblasts is preceded by the so-called pyramid stage (

E.maxima

, E.melea- gridis

, E.tetricis

, etc.). In the pyramid stage, the sporont extends 4 tapering processes, from which separate the round sporoblasts. The latter structures elongate and their further differentiation results in 2 sporozoites within each sporoblast. The pyramid stage Is short and occurs very likely with the majority of Eimeria but may have escaped attention because of its short course. Sporocysts containing 2 sporozoites have as a rule a micropyle (Stieda body) at one end. The sporozoites arrange parallelly in the sporocysts, with one end broadened and club-like, the other tapering, usually in head to tail position. By the end of sporogony 8 invasive sporozoites develop In each oocysts. Development of a primary or oocystic residual body is infrequent in the oocysts of the Eimeriae of gallinaceous birds. One or two polar bodies are more often seen inside the oocyst. In the overwhelming majority of the cases, the polar bodies arise by the end of sporogony, though they may sometimes be present already in freshly excreted oocysts.The aggregated or scattered granula occurring within the sporocyst outside the sporozoites is called the secondary or sporocystic residual body. The pre-