542 



Europe. Cytinus hypocistis is said to contain gallic acid. The species 

 of Rafflesia are gigantic parasites, the perianth being sometimes three 

 feet in diameter, and capable of holding twelve pints of fluid. They 

 are parasitic on the stems of species of Cissus, as well as on some 

 leguminous plants. It. Patma is employed in Java as an astringent 

 and styptic. 



SECTION II. CRYPTOGAMOUS PLANTS. 



CLASS in. ACOTYLEDONES, Juss. CELLULAEES AND MONO-CEYPTOGAME^E,Z)C'. 

 THALLOPHYTA AND ACBOBRYA, Endlich. THALLOGENS AND ACEOGENS, Lindl. 



1104. The plants belonging to this class, are in some instances 

 composed entirely of cellular tissue; in other instances, both cells and 

 vessels are present. The vascular tissue in the higher orders consists 

 partly of closed spiral and scalariform (fig. 62) vessels. Many of them 

 have no true stem nor leaves. The woody stem, when present, 

 consists of simultaneous vascular bundles, which increase in an acro- 

 genous manner (^T 103). The stem of Tree-ferns (which illustrates 

 this class) is unbranched, more or less uniformly cylindrical, hollow in 

 the interior, and marked by the scars of the leaves (fig. 116). Stomata 

 occur in the epidermis of the higher divisions. Leaves, when present, 

 have frequently no true venation, at other times the venation is forked. 

 There are nojlowers, and no distinct stamens nor pistils. Reproduction 

 takes place in some cases apparently by the union of cells of different 

 kinds (antheridia and pistilidia) (^[ 492), by means of which ger- 

 minating bodies called spores are formed (fig. 498). In other cases it 

 is difficult to trace this process of fertilization. The spore may be con- 

 sidered as a cellular embryo which has no cotyledons, and germinates 

 from any part of its surface, being heterorhizal (^[ 591, fig. 530). 



Subclass 1. ACBOGENJS OK CORMOGEN.E.* 



1105. Acotyledons, having usually distinct stems and leaves, stomata, 

 a certain amount of vascular tissue, and thecse or cases containing 

 spores. This subclass corresponds in a great measure with the division 

 of Cormophyta, called Acrobrya by Endlicher, and with the Foliosse 

 or uEtheogamaB of De Candolle. 



1106. Order 212. Eqnfeetaceie, the Horse-tail Family. Stem 

 striated, hollow, usually branched, containing much silica in its com- 

 position, articulated, the joints being separable, and surrounded by a 

 membranous toothed sheath. There are no true leaves, green-coloured 



* 'A*{, summit, xoeuiiis, a stalk or stem, and rintiti* to produce. 



