Nerve supply as a stimulator of the growth of tissues including skin *

Summary It is common for benign excesses of cutaneous tissues in man to be associated with excessive innervation of the tissue concerned. The examples discussed and illustrated include certain ‘benign tumours’, supernumerary digits, traumatic neuromas, etc. The question raised by these simple observations is that of cause and effect. Does an autonomous benign excess of peripheral tissue somehow attract to it an increased nerve supply from the centre, or may increased innervation from the centre of the body itself induce or promote excessive tissue growth at the periphery ? This problem will first be considered in the light of human cutaneous pathology. It will then be pursued through an initial programme of animal experimentation designed to parallel as closely as possible the human problem.