Dr. Kassai Tibor - Dr. Murai Éva szerk.: Parasitologia Hungarica 8. (Budapest, 1975)

Pores of the excretory duct and Laurer's canal open 2600-2650 u and 2850-2900 u, respectively, from the posterior end of the body. Gastrodiscus aegyptiacus (Cobbold, 1876) (Figs. 6-13) This fluke is a common parasite of equines in Africa and India. The pharynx is of the Gastrodiscus type (NÄSMARK, 1937) and associated with a pharyngeal bulb (Figs. 6-8) and secondary pharyngeal sacs (Figs. 8 and 9), Though GUPTA et al. (1971) have found the same structure as NÄSMARK did, according to their figure (206 p., Fig. 4) the anterior sphincter seems to be bigger than the reported by NÄSMARK. In our material - in accordance with NÄSMARK's finding - the anterior sphincter consists of some muscle units near the anterior end of the middle circular layer (Figs. 6 and 7). The structure and the number and arrangement of muscle layers of the acetabulum were both as described by NÄSMARK for the Gastrodiscus type (Figs. 11 and 12). The genital atrium was not characterized by NÄSMARK. There are neither papillae nor genital sphincters (Fig. 10). The genital papilla may be protruded or retracted in appearance, radial musculature of the genital atrium well developed. Pars prostatica 250-300 u long, prostatic gland cells were not seen. The cirrus pouch with faint muscle elements in its wall (Fig. 11). Muscle layer in the wall of the internal vesicula seminalis fairly developed. The metraterm and the ductus ejaculatorius are lined with tegument and the former is surrounded by fairly strong circular musculature (Fig. 10). In the literature there are conflicting views on the presence of the cirrus pouch. LOOSS (1896) and YAMAGUTI (1958) have stated its presence, while WILLMOTT and PESTER (1961) and GUPTA et al. (1971) did not report its occurrence. In our opinion there is cirrus pouch (Fig. 13) in this species but its musculature is poorly developed. It was found that the external vesicula seminalis was several times longer than the internal one and formed 10-13 convolutions along its way from the anterior testis up to the vesicula seminalis interna. The internal vesicula seminalis can be considered to be analogous with the pars musculosa in species having no cirrus pouch. On the basis of examination of five species having cirrus pouch a correlation was found between the degree of development of musculatura of the cirrus pouch and the musculature of the wall of the internal vesicula seminalis. In cirrus pouch with well developed musculature an internal vesicula seminalis with feeble musculature is normally seen. On the other hand cirrus pouch with slightly developed muscle elements have internal vesicula seminalis with fairly well developed musculature. It appears that the reason of this correlation is functional, i. e. passing of sperm into the ductus ejaculatorius. The excretory duct and the Laurer's canal don't cross each other, their pores open at 2000-2081 p and 3750-3780 ja distances, respectively, from the posterior end of the body. Figs. 1-5: Median sagittal sections of Chiorchis fabaceus - 1 = Pharynx with primary pharyngeal sacs; 2 = Genital atrium; 3-4 = Ventral and dorsal halves of acetabulum; 5 = Dorsal part of acetabulum with a layer of muscle units; Figs. 6-9: Median sagittal and cross sections of Gastrodiscus aegyptiacus - 6 = Pharynx with pharyngeal bulb; 7 = Cross section of pharynx; 8 = Cross section of pharyngeal bulb at the junction of secondary pharyngeal sacs; 9 = Cross section of secondary pharyngeal sacs;