THE FUNDAMENTAL SYSTEM. 123 



in the following list of examples is observed : (1) the rhizomes and 

 roots of ferns ; (2) stems of Selaginella and Lycopodium ; (3) stems of 

 Monocotyledons ; (4) stems of Equisetum ; (5) young stems of Gymno- 

 sperms and Dicotyledons ; (6) roots of Phanerogams ; (7) reduced 

 bundles of leaves. 



(c) The discussion of the disposition of the bundles in the stem, and 

 their relation to the leaf bundles, together with the development and 

 structure of secondary bundles, belongs properly to the special anatomy 

 of the Phanerogams. (See Chapter XX.) 



IV. THE FUNDAMENTAL SYSTEM, OR THE SYSTEM OF 

 GROUND TISSUES. 



153. These terms refer to the mass of various tissues 

 lying within the epidermis, and not included in the fibro- 

 vascular bundles, when they are present. In passing down 

 through the lower plants this inner mass becomes more and 

 more simple, until it is composed of but one homogeneous 

 tissue, when the term system can no longer be profitably 

 applied to it ; in passing to the higher plants, on the other 

 hand, there is in this portion of their structure an increasing 

 complexity, which comes at last to more than equal that of 

 either the epidermal or fibro- vascular systems. 



154. In its fullest development, the fundamental system 

 may contain parenchyma of various forms, collenchyma, 

 sclerenchyma, laticiferous tissue, and possibly also fibrous 

 tissue.* Their arrangement, within certain limits, presents 

 a considerable degree of similarity in nearly related groups 

 of plants, but this is by no means as marked as in the case of 

 the fibro-vascular system. 



* It is a question whether fibrous tissue occurs in the fundamental 

 system ; there are some cases (e.g., in Ferns, Lycopodiaceae, etc.) 

 which appear to show that it does, but possibly they admit of other in- 

 terpretation. It should be mentioned here that many eminent botanists 

 (notably Schwendener, Russow, Falconberg, and De Bary) hold that all 

 fibrous tissue belongs to the fundamental system, and as a consequence, 

 that it in no case is a proper constituent of the fibro-vascular bundle. 

 This is, however, nothing more than making a typical form of bundle 

 (composed of tracheary and sieve tissues), and then insisting that all tis- 

 sues not found in the type are extra-fascicular, a course which cannot 

 be followed in this book. 



