. Comparative anatomy of the vegetative organs of the phanerogams and ferns. Plant anatomy; Phanerogams; Ferns. fs S3 M rj 22 iff s-y- t3 \'to\ iS \f2\f7 9 \/'f I// \fO. Fig. 109. —Thuja plicata, after Geyler. A scheme of the bundle system, the cylindrical surface being reduced to one plane. B (16) trans- verse section through ayoung shoot. I, I the bundles, which pass directly into a pair of leaves ; outside each, below the surface, is a resin pas- FiG. no.—Pinus sylvestris, after Geyler. Scheme of the vascular system in the young shoot, the cylindrical surface being reduced to a single plane
. Comparative anatomy of the vegetative organs of the phanerogams and ferns. Plant anatomy; Phanerogams; Ferns. fs S3 M rj 22 iff s-y- t3 \'to\ iS \f2\f7 9 \/'f I// \fO. Fig. 109. —Thuja plicata, after Geyler. A scheme of the bundle system, the cylindrical surface being reduced to one plane. B (16) trans- verse section through ayoung shoot. I, I the bundles, which pass directly into a pair of leaves ; outside each, below the surface, is a resin pas- FiG. no.—Pinus sylvestris, after Geyler. Scheme of the vascular system in the young shoot, the cylindrical surface being reduced to a single plane; leaves arranged 8/ji, in a right-handed spiral. The figures indicate the successive bun- dles of the leaf-trace, which are represented as broad bands. Each pair of converging bundles (represented as thin lines), near the emerging bundles o—9, goes to an axillary shoot. The traces unite in descending order, each with the eighth lower one. dicular and parallel course downwards through two internodes, and inserts itself in the third node laterally on the trace which emerges at node 2, each bundle joining with that laterally next it. In the node there appears at an early stage a transverse girdle of tracheides, which unites the bundles. Strasburger states for Ephedra campylopoda, that between the two bundles of the trace of each leaf there runs a ' complementary bundle' which arises from the girdle of tracheides: this passes through one internode, from the node of the pair of leaves, to the next transverse girdle. In Ephedra altissima, according to the same author, the two bundles of the trace of a leaf take a separate course only in their own internode, and in the next are united to a single bundle. E. vulgaris has therefore eight bundles of the trace in the internode, of these two opposite pairs belong to the same pair of leaves : E. campylopoda has ten, E. altissima only six. The species of Gnetum have on their foliage shoots decussating pairs of leaves, separated from o
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Keywords: ., bookcentury1800, bookdecad, booksubjectplantanatomy, bookyear1884
