IV 



in some species^ yet becomes arborescent in others, and often 

 attains a considerable height ( Cyathea, Alsophila), This- 

 caudex, wiiich is hollow within, and not possessed of a fibrous 

 inner bark {liber^, is generally hard from without, and of a 

 glossy appearance. Both the root-stocks and the stems of 

 some of these plants contain peculiar resinous substances 

 which have anthelmintic properties, and serve as vermifuges, 

 {Lastrea athamantica, etc.,) — a fact, already known to the 

 ancients. — Theophr. Hist. Plantar, 18, 8. 



§ 5. In the formation of the leaves, nature has displayed 

 her wondrous charms. These leaves are called fronds by 

 botanists, and are either stalked, or more rarely sessile, or 

 sometimes jointed to the caudex,or root-stock, by articulations. 

 They are persistent and evergreen within the tropics and 

 temperate zones, but deciduous in cold climates, in which 

 case the frond is yearly renewed. Then- texture is herba- 

 ceous, membranaceous, or leathery; their upper surface, 

 generally dark, smooth, glazed or shining ; the under side, 

 on the contrary, paler, very veiny, often clothed with short 

 hair, and furnished with minute breathing pores {stomaia). 

 In a few genera, only, both surfaces are nearly alike ( Vit- 

 taria, Hymenophyllece). The fronds are rarely simple and 

 entire, much oftener lobed, digitate, or pinnatifid, but mostly 

 pinnate or further divided. Their pinnce and pinnules, again, 

 are entire, notched, sawed, toothed, incised, or pinnatifid, and 

 frequently unequally shaped at their bases. 



§ 6. The stipes, which in this family represents the leaf- 

 stalks of phanerogamous plants, is connected with the stem 

 or the rhizome by articulation. It is of different size : almost 

 wanting in some species, or of considerable length in others ; 

 mostly herbaceous, but sometimes woody, and covered by an 

 epidermis, which in the course of growth becomes brittle, 

 glossy, and of a dark-brown or blackish hue. The continu- 

 ation of the stipes through simple fronds goes by the name of 

 rib, or costa, while its further ramifications in pinnated 

 fronds are called rcichises. 



