. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. LIVERWORTS 399 of the archegonia hang down. This stalked structure with the finger-like branches is an archegoniophore. Some liverworts do not have archegoniophores; their archegonia are embedded in the thallus with the necks up and open at the top. As you have already guessed, it is down the neck that the sperms pass to the egg. The sperms are borne in organs called antheridia, a term which you used to describe the sperm-bearing organs of thallophytes. Th
. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. LIVERWORTS 399 of the archegonia hang down. This stalked structure with the finger-like branches is an archegoniophore. Some liverworts do not have archegoniophores; their archegonia are embedded in the thallus with the necks up and open at the top. As you have already guessed, it is down the neck that the sperms pass to the egg. The sperms are borne in organs called antheridia, a term which you used to describe the sperm-bearing organs of thallophytes. The anthe- ridia of liverworts produce great numbers of sperms. (See Figure 197) All the sperms of bryophytes are very small and bear two cilia. In the picture of Marchantia {Figure 195) you have noticed those branches whose flat tops are scalloped at the margin. These are antheridiophores and the antheridia are found em- bedded in their flat tops. They open on the upper surface. An- theridia are borne in other ways by other liverworts. Perhaps you have already wondered how fertilization is accomplished in Marchantia. You know that in some way the sperms must reach the eggs or else all these struc- tures that we have been describing are of no use to the plant. Sperms are not like pollen; they are not blown by wind or carried by insects. In order to move they need water; they swim actively by means of their moving. A Fig. 196. — Archegonia of Marchantia. A, a mature archegonium, ready for fer- tilization. B, young stage, showing the row of central cells of which the lowest becomes the 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 Coulter, John G. (John Gaylord), b. 1876. New York, American Book Co
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1913
