. Plants and their uses; an introduction to botany. Botany; Botany, Economic. 518 LIFE-HISTORIES. Fig. 341, I.—Umbrella-liverwort. Female plant (i), bearing archegonia- earriers (archegoiiiophores). (Atkinson.) tophyte develops from a spore in much the same waj^ as happens with the other liverworts described. P^ven more than in Riccia it is like the thallus of ColeooliKte, notably in possessing but a single chromatophorc in each cell, and in having no trace of pseudo-lea-\'es (Fig. 343). The gametangia are completely emljedded in the thallus (Fig. 344). Tlie embryo (E) develops a somewhat expa
. Plants and their uses; an introduction to botany. Botany; Botany, Economic. 518 LIFE-HISTORIES. Fig. 341, I.—Umbrella-liverwort. Female plant (i), bearing archegonia- earriers (archegoiiiophores). (Atkinson.) tophyte develops from a spore in much the same waj^ as happens with the other liverworts described. P^ven more than in Riccia it is like the thallus of ColeooliKte, notably in possessing but a single chromatophorc in each cell, and in having no trace of pseudo-lea-\'es (Fig. 343). The gametangia are completely emljedded in the thallus (Fig. 344). Tlie embryo (E) develops a somewhat expanded foot which serves to liold the slender sporophyte in an upright position, and functions also as an organ of absorption. As the sporophyte continues to grow, however, it is plain that scarcely more than inorganic materials are taken in; for very soon, above the foot ap- pears an elongating zone of tissue containing much chlorophyll; and this enables the sporophyte to photosynthesize and so, unhke our other liverworts, to be ahnost self-supporting. If an Anthero- ceros sporophyte ever develop a root it would no longer need to he even a partial parasite, as now, but co>ild lead an entirely independent existence. Tlie elongating region connecting the cap- sule and the foot is mori)liologically a shoot, and thus we have in this little phint th(> beginnings of a differentiation into tliree mem- bers—sporangimn, foot, and shoot. At the center of the shoot and. 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 Sargent, Frederick Leroy, 1863-. New York, H. Holt and Company
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1913
