. Comparative anatomy of the vegetative organs of the phanerogams and ferns. Plant anatomy; Phanerogams; Ferns. LATICIFEROUS VESSELS. 169 whether those coagula are really latex which came as such from the tubes, and not products of coagulation of fluids which had diffused through the walls of the vessels. Sect. 47. The distinctions of the two categories of laticiferous tubes depend upon certain phenomena of their development and form. The articulated series, as types of which those of the Cichoracese, Papaveracea;, and Papayaceae may serve, arise from series of elongated cells of the meristem
. Comparative anatomy of the vegetative organs of the phanerogams and ferns. Plant anatomy; Phanerogams; Ferns. LATICIFEROUS VESSELS. 169 whether those coagula are really latex which came as such from the tubes, and not products of coagulation of fluids which had diffused through the walls of the vessels. Sect. 47. The distinctions of the two categories of laticiferous tubes depend upon certain phenomena of their development and form. The articulated series, as types of which those of the Cichoracese, Papaveracea;, and Papayaceae may serve, arise from series of elongated cells of the meristem (or cambium), which coalesce, by perforation of their septa, to tubes. In the simplest case, which occurs in Musa and Chelidonium (Figs. 80, 81), the tubes remain simple, or are branched, and con- nected in a net-work only inasmuch as one series of their original members may. Fig. 80. — Chelidonium majus; tangential section through the secondary cortex of an old root; m—m and *—* portions of milk- tubes between the cells of the parenchyma. At u—a tit passes beneath the parenchymatous cells (225). Fig. 81.—Chelidonium majus ; : section, part of a milk-tube with tum at s (225). :m, cortex, radial perforated sep- continue its course from any given point as two diverging series, and conversely. The septa between the original members are here perforated only in the middle by one or few holes; their margin is persistent; occasional large openings in the lateral wall also occur in rare cases, where two tubes are directly contiguous. In the majority of really typical cases the septa between the members of each series soon disappear completely, so that in the mature tube no trace of them re- mains. Occasionally in such cases single septa may persist through Hfe. The tube puts out lateral protrusions, usually at numerous points, which force. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability
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