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. _Production of vegetables._ We comprehend under this designation all the parts of vegetables or products of the vegetable kingdom, which are of sufficient interest to merit collection; such as vegetable fibre employed in the fabrication of tissues or cordages; natural tissues coming from the preparation of the bark of trees; paper, made directly from certain plants; starches, with the starch prepared at the place where the plant grows, tubercles root, branches and seeds from which it is extracted; gums, sugars, resins, vegetable wax, and other concrete sugars elaborated by vegetables; dye stuffs; besides, roots, barks, leaves or fruit, used either in medicine or the industrial arts. It is essential, as much as possible, to join to these objects, with a label of the same number, a sample in a herbal of the plants which produce them; and to give the common name both of the plant and the stuff used, and the uses to which it is applied. Samples gathered with these precautions in the countries where these products are developed would be interesting even for the objects which generally arrive in Europe through commerce; for, in great number of cases, the origin of these stuffs is obscure, the distinction of their kind and different qualifies very difficult, and many of them are adulterated by falsifications or secondary preparations. It would be well to send a sufficient quantity of each of these stuffs for certain experiments which may be judged interesting; from one to two kilogrammes would generally be a suitable quantity. The stuffs that are liable to be attacked by insects should by placed, well dried, in boxes, bottles or earthern jars perfectly sealed. _Specimens relating to vegetable anatomy and physiology._--Many objects useful for extending the study of these branches of botany are comprehended in the collections of trunks, fruits and dried plants which we have already particularised; we recommend here, under this special tittle, the collection of samples which would show the deviation from the usual structure of vegetables, or those which must be preserved in a particular manner in order to be submitted to observation. Such are: 1º The results of experiments tried, frequently, for a different end, on vegetables which do not grow in Europe--