"It will be seen," he observes, "in the course of this work, how easy it would be to imagine parts of the same specimen to be different species, when they happen to be broken and dispersed. I can confidently assert, that in at least a thousand different specimens which I have had in my possession, not more than a hundred distinct species can be recognised. Furthermore, still fewer indeed can be referred to any living species; for it is not the fern-like leaf of a plant, the palm-like cicatrix, or the cane-like joint of a stem, that will suffice to identify them with those tribes of the vegetable kingdom. The whole anatomy of the plant must be studied. The subject has, indeed, been begun by Professor Martins, in his comparison of certain fossil stems of plants with those of the living plants growing in the Brazils, but the study is as yet too new to afford certain results. Accordingly, several of that professor's opinions are at variance with those of M. Adolphe Brongniart, who has also compared the recent and fossil vegetables together on this plan. But by following up the comparison, which has been so successfully adopted by Baron Cuvier, in the study of fossil animals,[93] similar results may be expected, and a knowledge of the extinct plants be at length attained." [Footnote 93: Recherches sur les Ossemens Fossiles.] Mr. Artis then gives an abstract of the systems of Baron Schlotheim, Count Sternberg, Professor Martins, and M. Adolphe Brongniart, which I am Induced to subjoin as a useful record of the state of fossil botany twelve years ago:-- "The Baron Schlotheim, who published in 1804 the first part of a Flora der Vorwelt, followed up his researches of this kind by a catalogue of his cabinet, under the title of 'Die Petrefactenkunde auf ihrem jetzigen Standpunkte erläutert,' published in 1820, to which two Appendices have since been added in 1822 and 1823. "The arrangement made by the Baron, so far as regards the vegetable part of his cabinet, is as follows. His specimens are first divided into five Sections, or Orders:-- 1. Dendrolithes, containing the remains of trees, which are subdivided into three sub-sections. A. _Lithoxylites_, of which no characters are given, but from the specimens mentioned by him, he evidently arranges in this place the wood-stone and wood-opal of the mineralogists. B. _Lithanthracites_, in which are placed the bituminized stems, and other parts of trees. C. _Bibliolithes_.--Fossil leaves, mostly of the later formations. 2. Botanolithes.--Comprising those kinds of fossil plants which cannot be considered either as trees or shrubs, nor as belonging to the plants of the old coal formation. All the specimens belonging to the preceding sections are merely enumerated, and not distinguished by generic and trivial names, as is the case with the following. Phytotypolithes.--Fossil plants of the stone-coal formation. These are divided systematically into genera and species. The genera are as follow:--