Paper, 'On Bacterium decalvans: an organism associated with the destruction of the hair in alopecia areata' by George Thin Thin writes: 'Although Gruby, in the year 1843, announced that the affection of the hairy scalp known as alopecia areata (area celsi) is caused by a fungus, the parasitic theory of the disease has met with comparatively little support. If the patients on whom Gruby made his observations really suffered from this disease and not from ringworm, which in some of its forms is apt to be mistaken for it, this uncertainty is very remarkable.' Annotations in pencil and ink throughout. Includes one page of figures. Subject: Dermatology / Biology / Pathology Receivd 19 February 1881. Read 3 March 1881 / 22 December 1881. Communicated by [Thomas Henry] Huxley. A version of this paper was published in volume 33 of the Proceedings of the Royal Society as 'On bacterium decalvans: an organism associated with the destruction of the hair in alopecia areata'. An earlier paper of the same name was published by Thin in volume 31 of the Proceedings of the Royal Society. 1881