Nerve tissue, light micrograph. Cross-section of a myelinated peripheral nerve. The many empty-looking circles are myelin sheaths surrounding a central axon and appear empty due to the myelin being dissolved during the preparation of the tissue. The nerve is supported externally by connective tissue termed perineurium (green). Individual axons are supported by fine ramifications of endoneurium. Paraffin section, Masson's trichrome stain. Magnification: x150 when width printed at 10cm.