The cerebrospinal nerves consist of numerous nerve fibers collected together and enclosed in membranous sheaths. A small bundle of fibers, enclosed in a tubular sheath, is called a funiculus; if the nerve is of small size, it may consist only of a single funiculus; but if large, the funiculi are collected together into larger bundles or fasciculi, which are bound together in a common membranous investment. Examples include: Anterior funiculus of the spinal cord Lateral funiculus of the spinal cord Posterior funiculus of the spinal cord Funiculus solitarius of the medulla Funiculus separans [ http://en.wikipedia.org/wiki/Funiculus_(neurology) ]