1602. To them succeed the Lilies, which have a well-marked root, a more perfect, though still always herbaceous, stalk, and a few spathoid, more numerously ribbed leaves; lastly, their corollæ, ovaria, and seeds are perfect; but still they invariably have no genuine fruits. 1603. Finally, the Palms are elevated above all by their stem being rich in tracheæ and wooded, as also by the perfection of their fruit. Scientifically, the scapose or shaft-plants must also resolve themselves into three classes; into Bark-, Liber-, and Wood-plants. _CLASS IV._ _Bark-plants--Gramineæ._ 1604. In these plants the whole stalk must have assumed the form of the cortex or bark, and consequently be hollow--_tubular_, or _culmaceous plants_. 1605. A mere bark cannot ramify. But the tendency unto ramification is manifested as nodes--_nodose plants_. 1606. The leaf which still represents the bark, is only imperfectly slit up, and therefore still forms a tube. Such leaves are called tubular or spathe-leaves proper. 1607. Such tubular leaves being only half slit up can only shoot forth gradually from each other, and that indeed in such a manner that they stand actually by twos, encased in, or opposite to, each other. 1608. Since the blossom is, as it were, an impression, or copy of the leaves, so will it here also consist only of spathiform, involucral, or calycine leaves, and only of two, one of which, though opposite to, is surrounded by the other. Such floral parts are called glumes--_glumaceous plants_. If four glumes are present, then the external pair of them corresponds to the involucrum or spatha, the internal to the calyx. 1609. The corolla-petals are of necessity arrested in plants such as these, where no true leaf is as yet developed; frequently two only are left persistent as pellicles or _lodiculæ_. 1610. This is still more the case with the ovary and seed; in each only one leaf attains development, and the seed has entirely coalesced with the ovarium. This kind of fruit is called _caryopsis_. 1611. Nodose plants with hollow scape or shaft, tubular leaves, glumose blossoms, and cariopsidal fruits are _Grasses_. DIVISION. 1612. The Bark-plants pass moreover, together with their subdivisions, through the five stages of vegetable organs, and they will therefore produce also a more perfect stalk, leaves, and flowers. The whole calyx will, however, never be coloured or corolla-like in its character. Cortical plants are thus herbaceous plants with hollow stalk, and with an arrested or green calyx, without sarcose or fleshy fruit. 1613. Those, which have simply glumose flowers, are without doubt the lowest in rank, as corresponding to the tissues and stock, but not yet to the flower.