Ultrastructural study of the luminal surface of the ducts of the epididymis of gallinaceous birds

The Various ducts of the epididymides of four gallinaceous birds, the turke y (Meleagris gallopavo), domestic fowl (Gallus gallus), guinea-fowl (Numida meleagris) and Japanese quail (Coturnix coturnix japonica) were studied at the scanning and transmission electron microscopy levels. The tissues were fixed either by immersion or Vascular perfusion, for comparative purposes. Each duct system, save for a few details, presented similar morphological features in all species. The epithelial surface of the rete testis was regu lar and each cell bore a single cilium, as well as numerous, or in some par ts, very few, short, regular microvilli. Each of the Types I and II non-cil iated cells of the proximal and efferent ducts displayed abundant, moderate ly long and regular microvilli, and a solitary cilium. The ciliated cells e xhibited tufts of cilia. The Type III non-ciliated cell of the connecting a nd epididymal ducts exhibited a solitary cilium, and numerous microvilli wh ich were intermediate in length between those of the rete testis and those of the efferent ducts. Vascular perfusion of the avian epididymal tissue wa s the superior method of fixation because it minimised the developments of fixation artefacts. Apocrine secretion did not appear to occur in the epidi dymis of these birds as the apical blebs of Types I, II and III cells, whic h have previously been reported, only manifest in this study in inadequatel y fixed tissues, and were therefore viewed as being artefacts. The present findings suggest that the current terminology, as applied to the avian epid idymis, be retained.