[79] On the doubts which were entertained till after 1812 on the subject of stomata, see Mohl’s ‘Ranken und Schlingpflanzen’ (1827), p. 9.
[80] Franz Julius Ferdinand Meyen was born at Tilsit in 1804, and died as Professor in Berlin in 1840. He applied himself at first to pharmacy and afterwards to medicine, and having taken a degree in 1826 he practised for some years as a physician. In 1830 he set out on a voyage round the world under instructions from A. von Humboldt, and returned in 1832 with large collections. He was made Professor in Berlin in 1834. There is a notice of his life in ‘Flora’ of 1845, p. 618.
[81] Hugo Mohl (afterwards von Mohl) was born at Stuttgart in 1805, and died as Professor of Botany in Tübingen in 1872. His father held an important civil office under the Government of Würtemberg. Robert Mohl, also in the service of the Government, Julius Mohl, the Oriental scholar, and Moritz Mohl, the political economist, were his brothers. The instruction at the Gymnasium at Stuttgart, which he attended for twelve years, was confined to the study of the ancient languages; but Mohl early evinced a preference for natural history, physics, and mechanics, and devoted himself in private to these subjects. He became a student of medicine in Tübingen in 1823, and took his degree in 1828. He then spent several years in Munich in intercourse with Schrank, Martius, Zuccharini and Steinheil and obtained abundant material for his researches into Palms, Ferns, and Cycads. He became Professor of Physiology in Berne in 1832, and Professor of Botany in Tübingen after Schübler’s death in 1835, and there he remained till his death, refusing various invitations to other spheres of work. He was never married, and his somewhat solitary life of devotion to his science was of the simplest and most uneventful kind. He was intimately acquainted with all parts of botanical science, and possessed a thorough knowledge of many other subjects; he was in fact a true and accomplished investigator of nature. A very pleasing sketch of his life from the pen of De Bary is to be found in the ‘Botanische Zeitung’ of 1872, No. 31.
[82] But von Mohl expressed some doubts on this point in 1844 (‘Botanische Zeitung,’ p. 340).
[83] This tertiary layer was at first supposed by Theodor Hartig to be of general occurrence; von Mohl in 1844 considered it to be present only in certain cases.
[84] Anselm Payen (1795-1871) was born at Paris and was Professor of Industrial Chemistry in the École des Arts et Métiers in that city. His most important botanical works were his ‘Mémoire sur l’amidon,’ etc., Paris (1839), and his ‘Mémoire sur le développement des Végétaux,’ published in the Memoirs of the Academy of Paris.
[85] On this point, see von Mohl’s citation in ‘Flora’ of 1827, p. 13. I have not myself been able to consult the originals.
[86] See Meyen, ‘Neues System,’ ii. 344.
[87] Franz Unger was born in 1800 on the estate of Amthof, near Leutschach in South Steiermark, and was educated up to the age of sixteen in the Benedictine Monastery of Gratz. Having gone through the three years’ course of ‘philosophy,’ he turned his attention, by his father’s wish, to jurisprudence; but he abandoned this study in 1820, and became a student of medicine, first in Vienna, and afterwards in Prague. From the latter place he made a vacation tour in Germany, and formed the acquaintance of Oken, Carus, Rudolphi, and other men of science, and in 1825 of Jacquin and Endlicher, with the latter of whom he maintained an active correspondence on scientific subjects. Having taken his degree in 1827, he practised as a physician in Vienna till the year 1830, and after that date was medical official at Kitzbühl in the Tyrol. During these years he continued the botanical studies which he had commenced as a youth, and at Kitzbühl directed special attention to the diseases of plants, to palaeontological researches, and to enquiries into the influence of soil on the distribution of plants. At the end of 1835 he became Professor of Botany at the Johanneum in Gratz, and devoting himself there especially to the study of palaeontology, he soon became the most eminent authority on that subject. Having been made Professor of Vegetable Physiology in Vienna in 1849, he applied himself more to physiology and phytotomy. He retired from this position in 1866, and from that time forward lived as a private individual in Gratz, promoting scientific knowledge by the publication of popular treatises and the delivery of lectures. He died in 1870. Information respecting his personal character and his varied and copious labours in many departments of botanical science is given by Leitgeb in the ‘Botanische Zeitung’ of 1870, No. 16, and by Reyer, ‘Leben und Wirken des Naturhistoriker Unger,’ Gratz, 1871.
[88] Hermann Schacht was born at Ochsenwerder in 1824, and died in 1864 in Bonn, where he had been Professor of Botany since 1859.