. Anatomischer Anzeiger. Anatomy, Comparative; Anatomy, Comparative. )33 '- The term "epididymis" is a very unsatisfactory one and should no longer be used, as it is necessary to distinguish clearly between the coiled anterior end of the spermiduct (== vas deferens, Wolffian duct, mesonephric duct) and the so-called sexual portion (anterior portion or "cranial zone") of the mesonephros of Plagiostomes. Two portions of the mesonephros can be plainly distinguished, the function of the anterior of which ("Leydig's gland") is apparently to secrete the
. Anatomischer Anzeiger. Anatomy, Comparative; Anatomy, Comparative. )33 '- The term "epididymis" is a very unsatisfactory one and should no longer be used, as it is necessary to distinguish clearly between the coiled anterior end of the spermiduct (== vas deferens, Wolffian duct, mesonephric duct) and the so-called sexual portion (anterior portion or "cranial zone") of the mesonephros of Plagiostomes. Two portions of the mesonephros can be plainly distinguished, the function of the anterior of which ("Leydig's gland") is apparently to secrete the substance by which the sperms are bound together in the spermiduct to form „sper- matophores". The greater part of this portion con- sists of small glandular tubules, without Mal- pighian bodies; but in addition to these, larger segmentally arranged tubules are present; — these open into the sper- miduct (Figs. 2 and 3). The posterior portion ("caudal zone") serves as the functional kidney: it possesses numerous Mal- pighian bodies and is provided with special ureters. The whole of the mesonephros is seg- mented. The bean-shaped testis is suspended by a mes- orchium in which blood- vessels and the fine efl'erent ducts run. The peritoneum is folded on the dorsal surface of the testis between a pyrami- dal area in the centre of this region and its inner border, and a space is thus enclosed between testis and peritoneum. The ventral surface of the fresh testis presents two well-marked regions, — a green medullary, and a white cortical. Fig. 1. Right testis with anterior end of meso- nephros and spermiduct. Ventral aspect (X !)• <^, b, c Regions through which sections are drawn in Figs. 2—4. blood vessel; Miillerian duct; ms. mesonephros ("Leydig's gland"); spermi- duct ; ts. testis; efferent ducts of testis; network of effei-ent ducts on testis; longitu- dinal collector of efferent ducts; ' regi
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