Collections of wooden stalks or trunks of trees.
This collection should be made in a different manner, for the trunks of the monocotyledons and ferns, and for those of the dicotyledons. For the first, such as the palms, vaquois or pandamas, the dracœna or dragoniers and the ferns in trees, etc. whose structure varies in height according to the age of the trees, it would be desirable to obtain grown and entire trunks, from the root to the top of the tree, when transportation can be affected without difficulty or expense. But when the size of the trunks and difficulties of transportation are so great that it can not be conveyed entire, it should be sent in three pieces of 50 centimetres each in length, taken, the first at the base with the roots, the second in the middle, and the third from the top with the first clusters of leaves. When the trunks are very large, damp and hard to dry, it is well, to quicken their drying, to split them lengthwise through the middle, but the two halves should always be sent and round pieces cut cross wise from 6 to 10 centimetres thick.
For the dycotelodons vegetables one of the principal trunks or a perfectly healthy branch should be taken, and a portion of it 40 or 50 centimetres long preserved; the size best suited for samples is from 10 to 20 centimetres in diameter. Generally the age of the trunk or branch should be such as to have at the same time perfect wood and pulp; for the kinds of wood used for building, it is necessary that the samples should be taken from trunks large enough to give an idea of the physical qualities of the woods. The samples should be sent with the bark entire. If there is danger that they do not dry well and shrink, they should be sawed lengthwise, at some distance from the pith, so that it may remain perfect on one of the pieces, and even in that case, it is well to send, besides the two halves of wood sawed lengthwise, an entire round of from 5 to 6 centimetres thick.
All these samples of trunks whether monocotyledons or dicotyledons, should not be boxed or sent off before they are perfectly dry. They should until then be kept as much as possible far from insects. It is indispensable to give interest to these samples of wood, to label them with numbers corresponding with samples of branches with leaves and flowers or fruits dried botanically, so that they can be determined with precision.
These numbers should be written on the edge wood cut very plain, either with ink or black crayon, or, better, with paint. When the samples are few, they can be notched or marked with Roman characters cut deep in the wood. It is very important either in the catalogues or in the labels of the samples in the herbals to write the common names which the trees bear, in the country where the samples were gathered, as these names are more generally known for the great vegetables than for the little plants; and by this precaution new information can be more easily obtained concerning the trees.
After having indicated the manner of making collections we shall now go on to particularise the vegetables whose trunks we especially desire to obtain.
The collection of the museum is already rich in trunks of arborescent fern. Yet it possesses but very few of those which do not belong to the tribe of Cyathees, such as the Diplazium, Dicksonia, Lomaria, Angiopteris.
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 should be easily gathered when the great trees are cut down in the forest, round which twine these parasites. The common names which they bear in their country should be marked with care both for the creepers and the trees as well as the virtues ascribed to them, and the uses to which they are applied. It is essential for most of the parasites, even when they are not of large size, and especially of those which contain much water, like the trunks of the Cissus, to cut directly pieces some centimetres thick, as their organisation is better preserved than that of the larger trunks.
All the different pieces coming from one trunk should be labelled with the same number.