. Lectures on the evolution of plants. Botany; Plants. 74 EVOLUTION OF PLANTS the procarp, or carpogonium is, in the lowest forms (Fig. 20, A), a single cell much like the oogonium of the green algge, but there is no contraction of the egg-cell preliminary to fertil- ization. There is a more or less evident prolongation, known as the trichogyne (jf), developed from the carpogonium, and the motionless sperma- tium, on coming in contact with this, fuses with it and the walls of both cells are dissolved at the point of contact, and the contents of the male cell pass into the trichogyne and effect
. Lectures on the evolution of plants. Botany; Plants. 74 EVOLUTION OF PLANTS the procarp, or carpogonium is, in the lowest forms (Fig. 20, A), a single cell much like the oogonium of the green algge, but there is no contraction of the egg-cell preliminary to fertil- ization. There is a more or less evident prolongation, known as the trichogyne (jf), developed from the carpogonium, and the motionless sperma- tium, on coming in contact with this, fuses with it and the walls of both cells are dissolved at the point of contact, and the contents of the male cell pass into the trichogyne and effect fertilization. It is probable that in most cases there is a fusion of the nuclei of the spermatium and car- pogonium, but it has been claimed that sometimes this does not occur, the fusion of the protoplasm being sufficient to insure fertilization. The result of fertilization is not a resting-spore as in the green algae, but the carpogo^ nial cell sends out a large number of short branches. Fig. 20. —Fructification of the Red Algae; A, piocarp, or female organ of one of the simpler Bliodophyceae, Batracho- spermum; t, the trichogyne; c, the carpogonial cell; B, the same after fertilization; an, the spermatium united with the trichogyne; sp, spores budding out from the carpogonial cell; C, the antheridium of Polysiphonia; D, the multicellular procarp of Sper- mothamnium; t, the trichogyne; E, the procarp in the higher Rhodophyceae; t, the trichogyne; x, the auxiliary cell which is secondarily fertilized and produces the spores. (Figs. A, B after Davis; E, after Phillips.). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Campbell, Douglas Houghton, 1859-1953. New York, London, The Macmillan company
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