Scanning electron microscopy of epididymal ducts in the Japanese monkey (Macacus fuscatus) with special reference to the architectural analysis of stereocilia.

The luminal surface of the initial segment of the epididymal duct in the Japanese monkey was observed under a field emission type scanning electron microscope. The long, slender stereocilia projecting from the apical surface of the columnar cells were found to be closely arranged in a funnel-like form opening to the lumen. The funnels formed by stereocilia were also confirmed by observation of thin sections cut from the same specimen used for scanning electron microscopy and their bottom was located in the center of the vertex of each columnar cell.