Anatomical studies on the duct of epididymis of the fowl.

The epididymis of the fowl is very small and poorely developed locating close to thetestis. Its shape is observed to be slender and elliptical. There is a membrane around the epididymis which is hard to be observed clearly. The epididymis is divided into three parts: head, body and tail. According to animal species, however, its form is not always equal, for example, in the case of man and boar the head and tail are not so clear, and on the otherhand in the case of rabbit and guinea-pig the body and tail are connected by a narrow part, its boundary being very clear. According to animal species there is also a certain difference in the form of the duct of epididymis. In the case of horse and ram the efferent vessels gather together to make a larger vessel, and then they gather again to form the ductus epididymis. In the case of ox two to three efferent vessels gather individually and change into the ductus epididymis. As for rat KURODA (1942) made a detailel observation and reported that the epididymis seemed to consist of many ducts in appearance, though it is in fact a single ductulus efferentes curved and folded up. The authors made a serial section of the epididymis according to KURODA's method, and its detailed observation was done. The matureed 3-year-old fowl of Rhode Island Red (♂) was used for the experiment. The material was fixed by Zenker's solution, embedded in paraffin, cut 10p thick in series and stained according to the haematoxy-in-eosin double staining method. A single duct was taken up and its locus was sketched and traced on the section paper. The following results were obtained: 　In the case of fowl, as in that of rat, many tubuli seminiferi which branch off from the testis gather together forming a duct at last and reach extremitas caudata. The duct does not branch off into many ductuli efferentes as in the case of ox, ram and dog, and a ductulus efferentes curves and folds up in the epididymis. The small and closed ducts were observed sometimes to branch off from the ductuli efferentes, but the authors-were unable to trace them cearly.