Introduction to structural and systematic botany; and vegetable physiology, being a 5th and rev. ed. of the Botanical text-book, illustrated with over thirteen hundred woodcuts

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1870 Excerpt: ...into pollen commences, which answer to the centre of the four divisions of the parenchyma of a leaf, viz. the two sides of the blade, each distinguished into its upper and its lower stratum. So that the anther is primarily and typically four-celled; each lobe being divided by a portion of untransformed tissue, stretching from the connective to the opposite side, which corresponds to the margin of the leaf and the line of dehiscence. This appearance is presented by a large number of full-grown anthers: but the partition usually disappears before the anther opens, when each lobe becomes single celled. The normal anther is consequently considered as two-celled. In Menispermum and Cocculus, however, the anther is strongly four-lobed externally, and each lobe forms a distinct cell at maturity. 530. Viewed morphologically, therefore, the filament answers to FIG 479. Plan of a stamen as answering to a leaf; the upper part of the anther eat swiv, and the summit of a leaf represented above it. the petiole of a leaf; the anther, to the blade. The connective represents the midrib; the lobes or cells of the anther represent the two symmetrical halves of the blade; and the line of dehiscence is normally along the margins of the transformed leaf. "What in the leaf would be cells of parenchyma develop as 531. Pollen. This usually powdery substance consists of grains, of definite size and shape, uniform in the same plant, but often very different in different species or families. The grains are commonly single cells, globular or oval in shape, and of a yellow color. But in Spiderwort they are oblong; in the Cichory and Thistle tribes many-sided (Fig. 485); in the Musk-plant spirally grooved (Fig. 480); in the Mallow family (Fig. 483) and the Squash and Pump kin, beset...