128. In _parallel-veined_ leaves, the whole framework consists of slender ribs or veins, which run parallel with each other, or nearly so, from the base to the point of the leaf,--not dividing and subdividing, nor forming meshes, except by minute cross-veinlets. The leaf of any grass, or that of the Lily of the Valley (Fig. 113) will furnish a good illustration. Such parallel veins Linnæus called _Nerves_, and parallel-veined leaves are still commonly called _nerved_ leaves, while those of the other kind are said to be _veined_,--terms which it is convenient to use, although these "nerves" and "veins" are all the same thing, and have no likeness to the _nerves_ and little to the veins of animals. 129. _Netted-veined_ leaves belong to plants which have a pair of seed-leaves or cotyledons, such as the Maple (Fig. 20, 24), Beech (Fig. 33), and the like; while _parallel-veined_ or _nerved_ leaves belong to plants with one cotyledon or true seed-leaf; such as the Iris (Fig. 59), and Indian Corn (Fig. 70). So that a mere glance at the leaves generally tells what the structure of the embryo is, and refers the plant to one or the other of these two grand classes,--which is a great convenience. For when plants differ from each other in some one important respect, they usually differ correspondingly in other respects also. [Illustration: Fig. 113. A (parallel-veined) leaf of the Lily of the Valley. 114. One of the Calla Lily.] 130. Parallel-veined leaves are of two sorts,--one kind, and the commonest, having the ribs or nerves all running from the base to the point of the leaf, as in the examples already given; while in another kind they run from a midrib to the margin, as in the common Pickerel-weed of our ponds, in the Banana, in Calla (Fig. 114), and many similar plants of warm climates. 131. Netted-veined leaves are also of two sorts, as in the examples already referred to. In one case the veins all rise from a single rib (the midrib), as in Fig. 112, 116-127. Such leaves are called _Feather-veined_ or _Penni-veined_, i. e. _Pinnately-veined_; both terms meaning the same thing, namely, that the veins are arranged on the sides of the rib like the plume of a feather on each side of the shaft. 132. In the other case (as in Fig. 74, 129-132), the veins branch off from three, five, seven, or nine ribs, which spread from the top of the leaf-stalk, and run through the blade like the toes of a web-footed bird. Hence these are said to be _Palmately_ or _Digitately_ veined, or (since the ribs diverge like rays from a centre) _Radiate-veined_. 133. Since the general outline of leaves accords with the framework or skeleton, it is plain that _feather-veined_ (or _penni-veined_) leaves will incline to elongated shapes, or at least to be longer than broad; while in _radiate-veined_ leaves more rounded forms are to be expected. A glance at the following figures shows this. [Illustration: Fig. 115-120. A series of shapes of feather-veined leaves.]