The work of the physiologist Gaskell,1 reported in 1886, on the distribution of afferent nerve impulses initiated by the viscera later received clinical interpretation by Ross.2 Many observers contributed to its further development, among whom Head,3 Mackenzie,4 Morley5 and Lennander6 may be mentioned. Cutaneous areas were mapped out by a study of cutaneous superficial hyperalgesia, the distribution of the rash along the course of nerves in cases of herpes zoster and the direction of the subjective symptom referred pain. To Head is due the credit for mapping out the distribution of the afferent somatic nerves in cases of structural and functional changes in the pelvis of the kidney and the ureter. This accumulation of clinical data, however, has been based essentially on the zoning out of cutaneous areas by actual tactile approach, without complete consideration of the anatomic structures involved.
Though all this accumulated