Dr. Kassai Tibor szerk.: Parasitologia Hungarica 1. (Budapest, 1968)

been found on post-mortem examination, liver lesions being either absent or recognized only with difficulty. It is, therefore, not particularly surprising that because of their similarity to caecal coccidiosis of chickens, the caecal lesions have frequently been confused with coccidiosis. Fig. 1. Turkey liver with lesions characteristic of blackhead from the material designated „Tiszaroff". This liver is about 1/3 original size. Jellegzetes blackheades elváltozásokat feltüntető pulykamáj a „Tiszaroff" elnevezésű anyagból. Az eredeti nagyságnak kb. az egyharamda. The material designated „Tiszaroff" provides a good example of the inexplicable alternating incidence of lesions Involving either the caeca alone or both caeca and liver.The turkey flock of a collective farm, totalling approximately 15,000 birds, was housed in two premises several kilometres apart. Conditions of management amd feeding were similar in the two places and medication with Tikofuran against blackhead was carried out to an identical schedule.The outbreak of the disease occurred simultaneously in both premises with comparable morbidity. Yet