Among the woods of the dicotyledonous trees, we shall place, in the first rank all the woods employed in the arts and particularly in cabinet-making and dying; woods which we receive only in the state in which commerce brings them to us and which it would be very interesting to have complete with their pith and bark and especially with a branch in flower or fruit preserved in herbal which facilitates the determination of their scientific appellation. With the exception of a small number of woods of Brazil, which we have received in this manner, we have every thing to ask in this respect from Brazil as well as from Guyana and the Antilles, and samples suited to clear up the history different sorts of cabinet woods, fron woods, pallissander, yellow woods, etc. would be of great interest. We shall cite, besides, the wood of the fig-tree sycomore of Egypt, employed by the ancient Egyptians, those of the Meliacees or Cedrelacees of India, that of the Flindersia of New Holland. Under the point of view of vegetable anatomy, the other trees, which do not furnish woods employed in the arts, are not less interesting, and all should be collected; but the branches need not be so large, say from 8 to 10 centimetres in diameter. The countries which have not yet added anything to the collection, and in which are to be found the objects that we want, are in the ancient continent, Arabia, Persia, but, above all, China, Cochinchina and the great isles of Asia; New Holland and Van Diemen's Land, whose vegetation is peculiar and from which we have as yet scarce a single sample of wood; Senegal, the Cape of Good Hope, Madagascar and Abyssinia: in the New Continent, Mexico and California, Peru, Colombia and the Magellan. In these different localities, should be procured not only specimens of wood from large trees, but the principal stalks of shrubs and of the great ligneous plants which never obtain the same size in our climate. But among the dicotyledonous vegetables there is none that merit the attention of naturalists as the creeping ligneous plants known as so much lianes. Almost all these plants present a remarkable structure, more or less anomalous, which may throw a light on the mode of increase and nourishment of vegetables. Samples of these fruits, collected by MM. Gaudichaud, Perrottet, Guillemin, Melinon, have already suggested valuable ideas. But there are yet many gaps to fill up, and persons living in warm countries could supply us with important documents, by collecting not only portions of all these plants but by sending pieces if the stalks of sufficient size taken from the foot of the oldest trees with the roots of younger trunks; young branches of from one to two years old and branches with leaves and flowers dried botanically. The essential point would be for each kind to have the succession of its different ages from the branches of the first year with their leaves, flowers and fruits up to the oldest trunks; and the samples