Dr. Kassai Tibor szerk.: Parasitologia Hungarica 1. (Budapest, 1968)
identify by morphological and staining properties the animal, ( Histomonas ) or plant ( Candida ) , origin of the etiological agent, and partly to examine the histopathology of livers with various lesions. For this purpose,paraffin embedded sections were stained with hematoxylin and eosin, Mallory's stain and periodic acidSchiff (PAS). The initial hypothesis assumed that the two morphologically distinct lesions were due to two different etiological agents of blackhead. This assumption was supported by findings in the liver (designation „Boldogasszonyfa") of a turkey which on postmortem examination showed typical caecal lesions, but only enlargement and diffuse discoloration of the liver. Microscopic examination of this liver revealed large numbers of conspicuous round homogenous bodies (Pigs. 2a, 2b), 7-lO^tc in diameter, staining pale pink with eosin, vivid red with Mallory's stain and deep lilac with PAS. The parasites, clustered densely together, occupied the spaces between the rows of liver cells, sometimes giving the impression of being intracellular in location. A similar intracellular position was previously described by CHESTER and ROBIN (1900) although later TYZZER (1920) advocated the intercellular location of the parasites. In the particular case being described only a few parasites other than those mentioned above were found; they also stained pale pink but showed an internal structure. Pig. 2a. Causative agents of blackhead in a section from turkey liver, a: The round structureless bodies resemble fungi. Hematoxylin and eosin. X 300 Blackhead-kóroközók pulyka májában, a: A kerek,struktúra nélküli képletek gombára emlékeztetnek. Hem-eozin 300 X Pig. 2b. Magnified part of Fig. 2. PAS. X 1000 Uaz, mint 2a. PAS. 1000 X Fig. 3a. Causative agents of blackhead in turkey liver, a: Bodies resembling to Histomonas. Hematoxylin and eosin. X 300 Blackhead-kóroközók pulyka májában, a: histomonasnak megfelelő képletek. Hem-eozin. 3OO X Pig. 3b. Magnified part of Fig. 3a. Hematoxylin and eosin. x 800 7az, mint 3a. Hem-eozin. 800 X
