A schematic illustration of the developmental relationship of neurolemmocytes to myelinated and non-myelinated axons. Initially, each lemmocyte embraces multiple axons (top left). If the axons are destined to remain small and non-myelinated, the lemmocyte ensheathes many axons individually (lower left). If axons are destined to become large and myelinated, then lemmocytes proliferate, develop a one to one relationship with each axon, and rotate processes around the axon to produce a myelin sheath internode for every mm or less of length along the length of the axon.