. Text-book of botany, morphological and physiological. Botany. FIG. 312.—Development of the archegonia of Salvinia natans (after Pringsheim, x 150). FIG. 313.—Salvinia natans; median longitudinal section through the prothallium and young embryo ; A after the first three divisions of the oospore, / and // are separated by the basal wall; / the hypobasal segment divided by the wall y into the cells a and b; II the epibasal segment,divided by the wall 2 (transverse wall); cd axis of growth ; B embryo in a further stage of development, r rr first stage of the foot, s apical cell of the scutiform
. Text-book of botany, morphological and physiological. Botany. FIG. 312.—Development of the archegonia of Salvinia natans (after Pringsheim, x 150). FIG. 313.—Salvinia natans; median longitudinal section through the prothallium and young embryo ; A after the first three divisions of the oospore, / and // are separated by the basal wall; / the hypobasal segment divided by the wall y into the cells a and b; II the epibasal segment,divided by the wall 2 (transverse wall); cd axis of growth ; B embryo in a further stage of development, r rr first stage of the foot, s apical cell of the scutiform leaf, III—VI the succeeding segments, v apical cell of the stem ; m'vx A and B the closing cells of the archegonium (after Pringsheim).. sides, the two angles grow subsequently into long wing-like prolongations hanging down by the sides of the macrospore. The first archegonium makes its appearance on the median line of the elevated back immediately behind the growing anterior side of the prothallium; two other archegonia then invariably appear right and left of the first, so that they stand in a transverse row parallel to the anterior side. If one of these archegonia is fertilised there is an end of the growth of the prothallium; but if this does not happen, the prothallium continues to grow on its anterior side, and from i to 3 new transverse rows of archegonia are produced, each of which contains from 3 to 7. The long oosphere of each archegonium lies obliquely in the tissue of the prothallium^ so that the outer (neck). 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 Sachs, Julius, 1832-1897; Vines, Sydney Howard, 1849-1934. ed. and tr. Oxford, Clarendon press
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1882
