SummaryThe author reviews a series of 144 cases of radiculitis produced by hernia of nucleus pulposus. All patients recovered after operation. Comparing the localization of pains, and paresthesia with the localization of herniated nucleus the author tries to draw a picture of the radicular topography. His scheme is not too different from Keegan’s scheme.Pain, paresthesia or hypoesthesia do not involve the whole radicular territory as a rule but only one or two segments of it.Author analyses several possibilities between the spine and the spinal ganglion. Each root forms several radicles ; of these, the upper innerve the distal parts of the limbs, the lowest the most proximal parts of the radicular territory.Pains correspond to peripheral feelings exactly localized in the dermatome innerved by the involved spinal root.