. Text-book of botany, morphological and physiological. Botany. 1J2, MORPHOLOGY OF MEMBERS. transformed into the sporogonium, a structure without leaves, roots, or branches, the sole function of which is the production of spores. A new Moss-plant is, on the contrary, constituted by the production of a leaf-bearing shoot from a branch of the alga-like Protonema, which branches, strikes root (by root- hairs), and is independently nourished. The shoot first produced, from which are developed the rest, is termed the Primary Shoot; it is often more strongly developed than its lateral shoots, as in
. Text-book of botany, morphological and physiological. Botany. 1J2, MORPHOLOGY OF MEMBERS. transformed into the sporogonium, a structure without leaves, roots, or branches, the sole function of which is the production of spores. A new Moss-plant is, on the contrary, constituted by the production of a leaf-bearing shoot from a branch of the alga-like Protonema, which branches, strikes root (by root- hairs), and is independently nourished. The shoot first produced, from which are developed the rest, is termed the Primary Shoot; it is often more strongly developed than its lateral shoots, as in most Ferns, Cycadese, Coniferse, Palms, and Amentiferse. The primary shoot produces Lateral Shoots of the first order or Secondary Shoots, these again lateral shoots of the second order, and so on. Nevertheless it often happens that lateral shoots of any order take root and become detached from the primary shoot; they then assume all its peculiarities, and may equally be considered as primary shoots. But it also happens that the primary shoot itself is arrested at an early period, while new orders of shoots proceed from it which gradually become more vigorous, as in many bulbous and tuberous plants. Shoots which become detached from the mother-plant when but slightly developed, continue to grow by independent nourishment, and repeat the peculiarities of the primary shoot, are called GemmcB or Bulbils; they are often adventitious shoots; but bulbils may also be shoots of normal origin, as in many species of FIG. 127.—Asplenium decussatum; middle part of a mature leaf; its mid-rib si bears the pinnae //; at the base of one of these is formed the bud Kt which has also already put out a root (natural size). Now that we have already spoken of the origin of leaves, hairs, and roots, and entered sufficiently into detail on the more important points (Sects. 20, 21, 22), it only remains to go a little further into the various modes of origin of leaf-bearing shoots. (a) In man
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1882
