Light micrograph of a cross-section of a bundle of myelinated nerves identified by the rings of myelin sheaths (black) that surround a central axon. The connective tissue that supports the nerves (green) comprises perineurium enclosing each bundle of axons and endoneurium, very faint, spreading between individual axons. Paraffin section, osmium tetroxide/fast green stain. Magnification: x 175 when width printed at 10cm.