MONOCOTYLEDON ES. 



275 



curved line from their entrance into the stem at the base of the 

 leaf, towards the centre of the stem, and then bend outwards and 

 proceed downwards in a direction more parallel to the sides of 

 the stem (Fig. 277). The bundles formed later, in those stems 

 which increase in thickness, are not continued into the leaves. 



THE BRANCHING as a rule is very slight, the axillary buds of the 

 majority of the leaves never attaining development, e.g. in the 

 Palms, bulbous plants and others. As the cotyledon arises singly, 



FIG. 276. Transverse seclion of the 

 stem of a Palm: v v is the wood portion, 

 b b the bast portion of the vascular 

 bundles. 



FIG. 277. Diagrammatic represen- 

 tation of the course of the vascular 

 bundles, from the stem into the leaves 

 in a Monocotyledon. 



the succeeding leaves also must be scattered, but they are fre- 

 quently arranged in two rows (Grasses, Iris, etc). The first leaf 

 borne on a branch (the " Fore-leaf," 1 the bracteole, if on a floral 

 shoot) has generally, in the Monocotyledons, a characteristic form 

 and position, being situated on the posterior side of its own shoot, 

 and hence turned towards the main axis; it is sometimes provided 

 with two laterally-placed keels (Figs. 279 /, 290 0i), but the midrib 

 is often absent. It arises in some cases from two primordia, which 

 at the beginning are quite distinct, and thus has been regarded as 

 formed by two leaves. It is, however, only one leaf, a fact which is 

 evident from several circumstances, one being that it never supports 

 more than one shoot, and this stands in the median plane (Fig. 279). 

 THE LEAVES are amplexicanl, and have a large sheath but no 

 stipules ; the blade is most frequently long, ligulate, or linear, en- 

 tire, with parallel venation, the veins being straight or curved 



1 " Fore-leaf " is adopted as a translation of " Vorblatt." 



