A traveller may be puzzled, in the midst of the profusion of animal and vegetable forms which he sees around him, to know what to collect and what to leave. Books can be of little service to him on a journey, and he had better at once abandon all idea of encumbering himself with them. A few days study at the principal museums before he starts on his voyage may teach him a great deal, and the cultivation of a habit of close observation and minute comparison of the specimens he obtains will teach him a great deal more. As a general rule all specimens which he may meet with for the first time far in the interior should be preferred to those common near the civilised parts, and he should bear in mind that the few handsome kinds which attract the attention of the natives, and are offered for sale to strangers, are almost sure to be of species well known in European museums. He should strive to obtain as much variety as possible, and not fill his boxes and jars with quantities of specimens of one or a few species, but as some of the rarest and most interesting species closely resemble others which may be more common, he should avail himself of every opportunity of comparing the objects side by side. In most countries, as already remarked, the truly indigenous, and often the rarest, species are to be found only in the mountains at considerable elevations and in the primitive forests, the products of cultivated districts being nearly all widely distributed and well known. In Botany a traveller, if obliged to restrict his collecting, might confine himself to those plants which are remarkable for their economic uses; always taking care to identify the flowers of the tree or shrub whose root, bark, leaves, wood, etc., are used by the natives, and to preserve a few specimens of them. But if he has the good fortune to ascend any high mountain not previously explored, he should make as complete a collection of the flowering plants as possible, at the higher elevations. The same may be said of insects found on mountains, where they occur in great diversity—on the shady and cold sides rather than on the sunny slopes—under stones, and about the roots of herbage, especially near springs, on shrubs and low trees, and so forth; for upon a knowledge of the plants and insects of mountain ranges depend the solution of many curious questions regarding the geographical distribution of forms over the earth. In Reptiles, the smaller Batrachians (Frogs, Salamanders, etc.) should not be neglected, especially the extremely numerous family of tree-frogs; the arboreal, or rock-haunting species of Lizards seen out of reach, and the swift-running forms that inhabit sandy plains may be secured with a charge of dust-shot, the saloon pistol being especially handy for this purpose. Snakes should be taken without injuring the head, which is the most important part of the body: a cleft stick may be used in securing them by the neck, or they may be shot, and on reaching camp