Morphologic study of the efferent ductules of the pigeon (Columba livia).

The efferent ductules of the pigeon are localized in the epididymal region and are topographically divided into proximal and distal, both portions being lined with stereociliated pseudostratified epithelium. Transmission electron microscopy shows five distinct cell types: light, dark, and angular non-ciliated cells with possible apocrine secretory role cells and halo cells, possibly intraepithelial leucocytes. The proximal efferent ductules have the widest diameter among all ductules in the epididymal region.