STUDIES IN DENERVATION: G.-SEBACEOUS SECRETION.

THE need for inquiries into the physiological mechanisms underlying the secretion of sebum is indicated, not only by the lack of information concerning this function of the skin, but also by the fact that it has not as yet been determined how far perversions of secretion are the cause of various pathological conditions such as seborrheeic dermatitis. In these circumstances it seemed desirable to ascertain to what extent the sebaceous glands are under the control of the nervous system. The results of an investigation directed to this end will be reported in this paper, but it is first necessary to indicate the background of the study. As is well known the sebaceous glands are holocrine in nature and the secretion is the end product of cellular disruption. On a priori grounds it would seem unlikely that these glands would be activated by nervous influences, but Boeke (1934) has described a plexus of nerves investing the glands. He considered it to be sympathetic in origin and excitor in function though he noted that the individual cells are not innervated. Moreover, many authors such as Stein (1926), Pachur (1931), and Serrati (1938) have reported that sebaceous secretion is disturbed in various affections of the central nervous system, most notably in chronic encephalitis lethargica. Details of unilateral disturbances of secretion are furnished by Serrati. This has led to the tacit assumption that the sebaceous glands are activated directly by nerves. In further support of this position are the observations of Arloing (1891) on the ear of the ass which lead him to believe that the sympathetic fibres exerted both an excitatory and an inhibitory action. Also frequently quoted is the'case of supra-orbital neuralgia reported by Marschalko (1905) in which a seborrhoeic condition existed'in the area supplied by the nerve. Abel (1936) also appears to concur, for he states that sympathectomy abolishes sebaceous secretion. Contrary opinions indicating that the glands are not directly under nervous regulation are expressed in Starling's text book (1936) and by Goldsmith (1936). This would seem to be the view of the majority at the present time, but the literature does not reveal any reason for modifying the statement of Reid (1898) that " Nothing is definitely