Among contemporary botanists, we find that De Candolle[90] in the volume he contributed to Lamarck’s _French Flora_, quotes only from the earlier work of Acharius. He had probably not then seen the _Methodus_, as he uses none of the new terms; the lichens of the volume are arranged under genera which are based more or less on the position of the apothecia on the thallus. Flörke[91], the next writer of consequence, frankly accepts the terminology and the new view of classification, though differing on some minor points. Two lists of lichens, neither of particular note, were published at this time in our country: one by Hugh Davies[92] for Wales, which adheres to the Linnaean system, and the other by Forster[93] of lichens round Tonbridge. Though Forster adopts the genera of Acharius, he includes lichens among algae. A more important publication was S. F. Gray’s[94] _Natural Arrangement of British Plants_. Gray, who was a druggist in Walsall and afterwards a lecturer on botany in London, was only nominally[95] the author, as it was mainly the work of his son John Edward Gray[96], sometime Keeper of Zoology in the British Museum. Gray was the first to apply the principles of the Natural System of classification to British plants, but the work was opposed by British botanists of his day. The years following the French Revolution and the Napoleonic wars were full of bitter feeling and of prejudice, and anything emanating, as did the Natural System, from France was rejected as unworthy of consideration. In the _Natural Arrangement_, Gray followed Acharius in his treatment of lichens; but whereas Acharius, though here and there confusing fungus species with lichens, had been clear-sighted enough to avoid all intermixture of fungus genera, with the exception of one only, the sterile genus _Rhizomorpha_, Gray had allowed the interpolation of several, such as _Hysterium_, _Xylaria_, _Hypoxylon_, etc. He had also raised many of Acharius’s subgenera and divisions to the rank of genera, thus largely increasing their number. This oversplitting of well-defined genera has somewhat weakened Gray’s work and he has not received from later writers the attention he deserves. The lichens of Hooker’s[97] _Flora Scotica_, which is synchronous with Gray’s work, number 195 species, an increase of about 90 for Scotland since the publication of Lightfoot’s _Flora_ more than 40 years before. Hooker also followed Acharius in his classification of lichens both in the _Flora Scotica_ and in the _Supplement to English Botany_[98], which was undertaken by the younger Sowerbys and himself. To that work Borrer (1781-1862), a keen lichenologist, supplied many new and rare lichens collected mostly in Sussex.