DR. WITHERING’S “Arrangement of British Plants” in 1818 reached its sixth edition. This is less than half a century ago, and yet the whole number of species of Fungi described in that edition was only 564, of which three hundred were included under the old genus _Agaricus_. Less than eighty of the more minute species of Fungi, but few of which deserve the name of microscopic, were supposed to contain all then known of these wonderful organisms. Since that period, microscopes have become very different instruments, and one result has been the increase of Withering’s 564 species of British Fungi to the 2,479 enumerated in the “Index Fungorum Britannicorum.” By far the greater number of species thus added depend for their specific, and often generic characters, upon microscopical examination. The proportion which the cryptogamic section bears to the phanerogamic in our local Floras before 1818, now almost involuntarily causes a smile. Even such authors as were supposed to pay the greatest possible respect to the lower orders of plants could never present an equal number of pages devoted to them, as to the higher orders. Relhan, for instance, only occupies one-fifth of his “Flora Cantabrigiensis,” and Hudson one-fourth of his “Flora Anglica,” with the Cryptogamia. At the present time, it will be seen that, with a liberal allowance for “hair-splitting,” the number of British species of flowering plants scarcely exceeds three-fourths of the number of Fungi alone, not to mention ferns, mosses, algæ and lichens, and yet we have no “Flora” which contains them, and but a minority of our botanists know anything about them. If we need excuse for directing attention to some of the most interesting of these plants, let the above remarks suffice in lieu of formal apology.