A tin japanned vasculum, or what is perhaps better still, a black leather haversack, of larger or smaller dimensions as the case may be, suspended over the shoulder by a strap, is of course indispensable for holding the specimens gathered. The latter of these we have found to be more generally convenient, as we can take it with us also for a short ramble, without its attracting so much attention from curious rustics, as the less-known and more singular-looking vasculum. Two sets of instruments are also necessary for removing the plant from the substratum on which it grows, as well as for breaking off in many cases a thin portion of the latter along therewith. These are a geologist's hammer and chisel for such as grow on rocks, boulders, and stones; a gardener's pruning-knife for such as grow on trees, pales, and the ground; as also an ordinary table-knife for detaching, by insertion under them, such foliaceous species as can thus be separated from the substratum. To these must be added several sheets of soft and moderately thick paper, cut into different sizes (some newspapers suit remarkably well), in which to wrap up the individual specimens and prevent them rubbing against each other; a few card-boxes also, of various sizes, in which for greater safety to place any of the more brittle species, or fragments of the rarer ones, by themselves; and a pocket-lens of good magnifying power, by which we may be able to detect on the spot those minuter species which the naked eye can with difficulty distinguish. With these the lichenist is fully equipped for an excursion, whether "near at hand or far away," and, with waterproof and umbrella, is ready to take the field even in threatening weather. A good deal of discrimination must be used in the selection of specimens for removal, which, in all cases where such can be obtained, ought to be fertile, with both apothecia and spermagones fully developed. Hence, such as are too old or too young, may be passed by, as neither the spores nor spermatia, by which alone, in many instances, they can be determined, will be found in a normal condition, any more than the thallus itself. The specimens gathered ought in every case to be of sufficient size to show distinctly the character of the thallus and of the fructification. Where, however, the thallus, as it frequently does, spreads very extensively over the substratum, it will be sufficient to break off such a portion from the circumference towards the centre, as will give an adequate idea of the more important characteristics of the plant. This is a point of considerable consequence; for should a portion be taken off from the circumference alone, or from the centre alone, it will often be entirely unsuitable for showing the real nature of the plant, and be quite useless for purposes of description. A little experience, however, will serve to prevent the commission of a mistake, into which, judging from the number of imperfect specimens