1566. I therefore place in this class the _Coniferæ_ or trees with acicular foliage, because they have no ovarium, but naked seeds; and besides these, some other plants, though doubtfully, on account of their very abortive blossoms, as the Naiadaceæ. There are therefore Tracheal plants without and with stamina. The first portray the stock or trunk, the second, the thyrsus or blossom; they live mostly in dry situations, and produce resins or fetid matters. 1567. First order. _Parenchymatous ferns--Aquatic ferns._ I here place the aquatic ferns, because, as water-plants, they occupy a lower situation, because they support the fruits upon a radical trunk, and finally, because these fruit-vesicles have two kinds of contents, all of which seems to remind us of the fuci and lichens; they correspond to the Tremellini. 1568. Second order. _Sheath-ferns--Club-ferns._ Here commence the land ferns, and those kinds indeed whose so-called capsules open in a valvular manner, just as in the liverworts; or almost after the fashion of a pyxidium by an orifice, somewhat as in the mosses; the trunk is provided with squamose leaves or lobes, e. g. Lycopodiaceæ and Osmundaceæ; they correspond to the Confervaceæ. 1569. Third order. _Stem-ferns--Annular or Ring-ferns._ Here we meet with phylloidal involuted capsules or seeds upon the back of a stem that is likewise leaf-like; e. g. the typical or true ferns. 1570. They have rudiments of roots and a stem, together with foliage, because they are the prototypes of these three organs. 1571. The ring of their capsules corresponds to the midrib of the leaf. In the preceding order the capsule was only an upsprung stalk; but it is here an upsprung and unfolded leaf, the prototype of the bud-development. 1572. The fern-capsules, namely, the true seeds, are an accumulation of leaf-buds at the extremity of the fascicle of spiral vessels. The indusium is the upraised epidermis, which opens in a spathose manner; it consequently stands in the signification perhaps of the floral spathe or involucrum. They correspond to the Fuci. 1573. Fourth order. _Floral ferns--Fluviales._ If the tracheal plants be exalted unto the flower, male organs cannot fail in at once beginning to develop. I place therefore in this order the Naiadaceæ with very arrested blossoms, and simply stamina without calyx and corolla. The spiral vessels are rather doubtful. 1574. Fifth order. _Fruit ferns--Coniferæ._ Tree with imperfectly-formed spiral vessels, stamina without corollæ, seeds without ovarium; thus agreeing with the Cryptogamia even to the stamina; they form likewise sixteen families. (Vid. Tab. B.) SEXUAL PLANTS. 1575. So soon as the three tissues separate completely from each other into bark, liber, and wood, while the tracheæ are arranged circularly into several clusters or groups, does the antagonism of these organs also make its appearance, and exhibit itself as sex in the floral organs.