Light microscopy of the epididymis which is a single but highly coiled tube some 5 metres in length in humans, storing and conveying sperm from the testis to the vas deferens. The tube is lined with columnar epithelial cells that serve to confer fertilizing ability to the sperm. Sperm are seen in the central lumen. Movement of the sperm along the epididymis is caused by contractions of smooth muscle surrounding the tube. Magnification x20 when printed at 10 cm.