The forests of Paraguay, still little known, situated along the coast of the Atlantic, consist of ligneous _Compositæ_ and _Ilex paraguayensis_, the Paraguay tea, of which a large quantity is annually exported. In the Argentine Republic Auguste de Saint-Hilaire found only 500 species of plants, among which only fifteen belonged to families which are not European. When we reach the south coast of Patagonia and the Falkland Islands, a few brown and coriaceous _Graminaceæ_ and _Cyperaceæ_, such as _Dactylis cæspitosa_, _Carex trifida_, _Bolax glebaria_, _Cardamine glacialis_, _Veronica_, _Calceolaria_, _Aster_, _Opuntia Darwinii_, _Lomaria magellanica_ among the tree ferns, a few brambles, thickets of bilberries and _Arbutus_, include nearly the whole of the vegetation of these desert lands, where mosses, hepaticas, and lichens reign supreme. We now reach the southern part of South America. In the stormy region of Terra del Fuego thick forests cover the mountains, where they are sheltered from the wind, to the height of 1,500 feet above the level of the sea. _Fagus betuloides_ predominates there; then comes _F. antarctica_, accompanied by barberry and currant bushes. At the Island of Hermite, the most southerly point of the American Continent, there is still some arborescent vegetation. Hooker there observed eighty-four flowering plants and many cryptogams. A fungus parasitic on the beech (_Cyttaria Gunnii_) constitutes there a principal aliment of the miserable inhabitants of these gloomy regions. The Australian flora presents forms more ancient than any other contemporary vegetation. More than nine-tenths of the species found between 33° and 35° south latitude, in Australia, are absolutely limited to these regions. Many constitute completely distinct families; others form families which are scarcely represented in any other part of the globe. Those even which belong to groups more generally diffused disguise their natural affinities under forms isolated and unlike their congeners. The different species of two genera, namely, _Eucalyptus_ among _Myrtaceæ_, and _Acacia_ among _Leguminosæ_, form perhaps, from their number and dimensions, one-half of the vegetation which covers the country. Their leaves are reduced to phyllodes. Neither these phyllodes nor the limb of the real leaves are placed horizontally, like those of Europe and other parts of the world, but are perpendicular to the surface of the soil, so that the light shining between these vertical blades is not arrested, as in the case with our trees and bushes, in which the leaves are placed transversely one above the other. The effect produced by masses of Australian verdure is thus entirely different from that to which we are accustomed. The aspects of these forests particularly struck the first travelers who visited them, from the singular sensation communicated to the eye by this mode of distributing light and shade.