Paper, 'The "ginger-beer plant", and the organisms composing it: a contribution to the study of fermentation-yeasts and bacteria' by Harry Marshall Ward Ward writes: 'The author has been engaged for some time in the investigation of a remarkable compound organism found in home-made ginger-beer fermentations. It occurs as jelly-like, semi-transparent, yellowish-white masses, aggregated into brain-like clumps, or forming deposits at the bottom of the fermentations, and presents resemblances to the so-called Kephir grains of the Caucasus, with which, however, it is by no means identical. He finds that it consists essentially of a symbiotic association of a specific Saccharomycete and a Schizomycete, morphologically comparableto a Lichen, but, as met with naturally, invariably has other species of yeasts, bacteria, and mould-fungi casually associated with these.' Annotations in pencil and ink. Subject: Bacteriology / Zymology / Mycology Received 19 November 1891. Read 17 December 1891. A version of this paper was published in volume 50 of the Proceedings of the Royal Society as 'The ‘ginger-beer plant," and the organisms composing it : a contribution to the study of fermentation-yeasts and bacteria'. 1891