and packing of their contents. As all are aware, these contents are either leaves or flowers, or both, or at least their germs, which during winter are so well protected from the nipping frost, or rotting damp, by the covering of hard brownlooking scales which so closely invests them. Overlapping one another Fig. 10 these scales are assisted in their protective office in some cases by a covering of a hard dry varnish; in others, as in the poplars, horse chestnut-Fig. 10-&c. &c., from being glued together by a sticky resinous substance; whilst, in not a few instances, they have a warm woolly lining. Within these carefully-constructed coverings lies the future foliage-at present we refer only to leaf-buds -of the tree, packed most closely, most beautifully, and in very varied forms, according to the nature of the plant which bears it. Take any bud swelling to the bursting in spring, cut 10. Leaf-bud of Horse Chestnut, showing the overlapping, imbricated protected. scales by which the young leaves are it both across and lengthwise, and you will at once gain an idea of the disposition of the foliation or vernation, as it is called, of the future leaf. If your bud belongs to the oak, the rose, or various other plants, you will find the leaves doubled side by side, conduplicate; if it claims parentage from the maple, the lady's-mantle, or the birch, the leaves will lie plaited up like a fan. In some plants, the leaves, as it were, embrace one another; in others, they are rolled inwards, or, as in the primrose or cowslip— Fig. 69-outwards or backwards. In the fern tribes we find the very curious and beautiful circinnate or gyrate mode of foliation-Fig. 11 11. Hart's-tongue Fern, showing the peculiar gyrate mode of in which the whole leaf or frond, as it is called, and at the same time every segment of it, is rolled inwards upon itself. Many other modes of leaf-folding will the careful examiner discover, and he should mark them, not only as valuable distinctive characters between plants of different tribes, but as examples, and beautiful examples, of His handiwork "who hath made all things well." The packing of the flower and fruit bud, named by botanists its aestivation, will be considered in a future section. : THE LEAVES. Few are there who cannot appreciate the beauty at least, as the gaze falls upon some stately tree, "which proudly spreads the bough" in the full flush of its summer leafiness, or as the eye wanders over the foliage of every form, and of every shade of green, which decks the broad bosom of the earth at all times but how few, comparatively, know the use for which this enormous breadth of leafy expansion is designed, for what purpose it is exposed to the influence of the sun's heat and light, and to the vicissitudes of our ever-changing atmosphere! Few are aware that every perfect leaf is an organ of respiration, a breathing mouth of the plant to which it belongs; that through the little pores or stomates of its surface-see Fig. 1-constant changes and interchanges are going on with the surrounding atmosphere, whereby that atmosphere is continually purified, kept fit to support animal life, whilst at the same time it is made to yield to the plant materials for its continued growth. Through the leaves, too, pass all the peculiar juices by which different plants are characterized; exposure to the influence of light and air in the leaf being requisite before the sap can become the proper juice of the vegetable; that is, can possess the odour, flavour, medicinal or nourishing properties which are peculiar to the individual. Some plants, it is true, such as the cactus tribe, do not possess true leaves; but in such cases the duties of the leaf are performed by the green stem. A leaf, as all can see at once, is composed of two different structures-the ribs or veins, and the vegetable substance lying between them. The term rib is applied to the more prominent markings, the central-see Figures-being called the midrib; the less conspicuous markings are the veins. Moreover, it can scarcely have escaped the notice of the least observant, that throughout plants generally, the ribbing or veining is arranged according to two very distinct plans. In one set of plants, more especially in those which are common to temperate climates, the veining is netted, or reticulated, or branching-Fig. 12, &c.-as we see it in the elm, the oak, the rose, and, indeed, in the majority of our British native plants. Another division of plants, such as the grasses, the lilies, &c., we find characterized by the ribs or veins running directly parallel throughout the leaf-Figs. 18, 108, 111, 113. In tropical countries a considerable proportion of the vegetation is composed of plants and trees with such parallel veined leaves.* The outward marks upon the leaves are in themselves valuable and ready distinctions, and greatly add to the beautiful diversity of foliage; but to the mind of the botanist, they convey more than a mere surface character; they indicate the division of the flowering vegetable kingdom into two great sections, each distinguished by peculiarities which run through its members, which commence with the seed, and which stamp the stem, the leaf, the flower, till they end in the seed again. From the form of the seed, these two great sections of flowering plants are named. In * The palms, the bananas, the aloe, the bamboo, all belong to this section of the vegetable kingdom, and associate with them the beautiful and varied orchis family, of which we have many species in our own land. In plants with netted veins the seed has two lobes, or, as they are called botanically, cotyledons, as any one may see who opens a bean or pea-hence such plants are classed as DICOTYLEDONOUS. plants with parallel veins, on the other hand, such as wheat, oats, and barley, the seed has but one lobe or cotyledon; hence such are named MONOCOTYLEDONOUS.* It may readily be comprehended, that the immense variety of form, substance, position, &c., presented by leaves, must furnish botanists with many and valuable distinctive marks; at the same time, it must be evident that these distinctions necessarily call for a long catalogue of terms-too long, by far, for us to enumerate here—but yet one which ought |