Text-book of botany, morphological and physiological . Base of the bifurcation. From thenature of the case every base can only bi-furcate once ; but every branch may againbecome the base of a new bifurcation ^. A Mofiopodiiim arises when the gene-rating structure, following the direction ofits previous axis of growth, continues togrow at its apex, while lateral structuresof the same name grow beneath it inacropetal succession, the longitudinal axesof which are placed in an oblique or transverse direction to that of the generatingmember. The generating member, since it continues to grow during
Text-book of botany, morphological and physiological . Base of the bifurcation. From thenature of the case every base can only bi-furcate once ; but every branch may againbecome the base of a new bifurcation ^. A Mofiopodiiim arises when the gene-rating structure, following the direction ofits previous axis of growth, continues togrow at its apex, while lateral structuresof the same name grow beneath it inacropetal succession, the longitudinal axesof which are placed in an oblique or transverse direction to that of the generatingmember. The generating member, since it continues to grow during the branching,may form numerous lateral members; for all these it is the common base; hencethe name Monopodium (Figs. 109, 113, 124). Every lateral branch may againbranch in the same manner, and thus itself become a monopodium of the secondorder. Just as the dichotomy may consist of numerous bifurcations, so may amonopodium consist of several orders of monopodial branching. These definitions refer only to the rudimentary condition of the branchings,. Fig. 125.—Dichotomy of the thallus of Dictyota dkhotoviaafter Nageli); the order of development is according to theletters A—E; the letters t—z indicate the segmentations of theapical cell before it dichotomises ; i is the division-wall byw hich the dichotomy commences; 2—6 the segments of thenew apical cells. ^ Since we have to give here a narrower application to the term Direction of Growth, it willbe necessary to compare the following section on Direction of Growth and Symmetry. 2 In Cryptogams with apical cells it may be thought that dichotomy must necessarily bebrought about by longitudinal division of the apical cell. When the segments arise by transversedivision this is actually the case, as is shown in Fig. 125; but when the segments are arrangedin two or three rows, this would necessitate that the dichotomising wall proceeding from theapical surface of the apical cell should bisect its posterior angle, and thus hav
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1875
