THE NATURAL SYSTEM. 365 



them. Having effected the primary division, however, upon other 

 grounds, we turn this difference to subordinate, account ; and 

 therefore consider the higher Flowerless plants, which agree with 

 the series above them in so many respects, and which in their 

 composition have woody tissue and vessels, to constitute the dis- 

 tinct class of VASCULAR FLOWERLESS plants. For reasons already 

 explained (108), they have also been termed ACROGENS. All the 

 kinds below these, being composed of cellular tissue exclusively, 

 (though the cells are often drawn into filaments, which may even 

 have a spiral fibre generated upon their walls,) are CELLULAR plants. 



692. But the higher Cellular plants, such as Mosses, still dis- 

 play the proper type of vegetation ; they agree with those of high- 

 er grades in having an opposite growth, forming a distinct axis or 

 stem, which grows upward by buds and is for the most part sym- 

 metrically clothed with distinct leaves ( 105) ; while the Lichens, 

 Seaweeds, and Fungi, the most imperfect of vegetables, present 

 no distinction into stem, root, and leaves, no polarity, or growth in 

 two opposite directions, no buds, and no organs which are clearly 

 analogous to flowers. Their homogeneous tissue often tends to the 

 formation of flat, more or less definite expansions (the thallus), 

 which is the nearest approach to any thing like leaves ; in which 

 their simple spores are embedded. Hence they are termed Thal- 

 lopJiytes. If the line of primary division be drawn in view of these 

 important distinctions, as proposed by Unger and Endlicher, the 

 vegetable kingdom would be separated into two great, but unequal 

 series ; namely, 1st, the Cormophytes, or Stem-growing plants^ 

 those with a distinct axis of growth, elongating downward into 

 roots, and upward into stems, provided with leaves, and with flow- 

 ers or their analogues ; and 2d, the Thallophyles, which are stem- 

 less, rootless, leafless, and in every sense flowerless (106). 



693. Following the plan we have adopted, however, we have 

 only to distinguish this higher grade of Flowerless Cellular plants, 

 exhibiting a distinct stem, &., as a separate class, the ANOPHYTES, 

 represented by the Mosses, which, although of the simplest ana- 

 tomical structure, still emulate the higher or typical forms (105)^ 

 The remainder (94-103), embracing the Lichens, Fungi, and 

 Algce, form the last and lowest class, the THALLOPHYTES. To con- 

 sider their subordinate arrangement would quite surpass our limits. 



694. The general plan may be analytically expressed by the 

 following schedule. 



31* 



