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Show 330 PHYSIOGNOMY OF PLANTS. and Tasmania (Van Diem en Island). Casuarinas with their leafless, thin, string-like, articulated branches, having the joints provided with membranous denticulated sheaths, have been compared by travellers, according to the particular species which fell under their observation, either to arborescent Equisetacere (Horsetails) or to our Scotch firs. (See Darwin, Journal of Researches, p. 449.) Near the coast of Peru the aspect of small thickets of Oolletia and Ephedra also produced on my mind a singular impression of leafiessness. Oasuarina quadrivalvis advances, according to Labillardiere, to 43° S. lat. in Tasmania. The sad-looking Oasuarina form is not unknown in India and on the east coast of Africa. (23) p. 242.-11 Needle-leaved trees." The family of Ooniferre holds so important a place by the number of individuals, by theil: geographical distribution, and by the vast tracts of country in the northern temperate zone covered with trees of the same species living in society, that we are almost surprised at the small number of species of which it consists-even including members which belong to it in essential respects, but deviate from it in a degree by the shape of their leaves and their manner of growth (Dammara, Ephedra, and Gnetum, of Java and New Guinea). The number of known Ooniferre is not quite equal to three-fourths of the number of described species of palms; and there are more known Aroidere than Coniferre. Zuccarini, in his Beitragen zur Morphologic der Ooniferen ( Abhandl. der math em. physikal. Classe der Akademie der Wiss. zu Mtinchen, bd. iii. s. 752, 1837-1843), reckons 216 species, of which 165 belong to the Northern and 51 to the Southern Hemisphere. Since my researches, these proportionate numbers must be modified, as, including the species of Pinus, Cupressus, Ephedra, and Podocarpus, found by Bonpland and myself in the tropical parts of Peru, Quito, New Granada, and Mexico, the number of species between the tropics rises to 42. The most recent and excellent work of Endlicher, Synopsis Coniferarum, 184 7, contains 312 species now living, and 178 fossil species found in the coal measures, the bunter-sandstone, the keuper, and the Jurassic formations. The vegetation of the Ancient World offers to us more particularly forms which, by their simultaneous a~nity with several |