Between 1869 and 1894 James Crombie contributed substantially to the literature of lichenology; many of his publications concern additions to the British flora, others are reports on collections of exotic material, and several relate to the debate occasioned by the discovery that lichens are composite organisms. Crombie is, however, remembered principally for his descriptive catalogue of the collections in the then British Museum (Natural History), the first part of which was published in 1894 under the title A monograph of lichens found in Britain. In preparing that work – and most of his other publications – Crombie received considerable help from the foremost lichen taxonomist of the day, William Nylander (1822–1899), with whom he began a 25-year correspondence in 1868.
Source: Extracted from: M. E. Mitchell (2003) 'The preparation and publication of James Crombie's A monograph of lichens found in Britain (1894), as documented in his letters to William Nylander', Archives of Natural History April 2003, Vol. 30, No. 1 : pp. 40-55