Examination of the cellular content of peripheral nerve fascicles has brought evidence that approximately 85% of these cells are Schwann cells and less than 5% may be fibrocytes, but are possibly macrophages. This change in the classification of the cellular content is attributed to inability to distinguish small non-myelinated fibers with the light microscope. The observations are discussed in relation to Wallerian degeneration and neoplasms of peripheral nerves.