. Foundations of botany. Botany; Botany. 252 FOUKDATIONS OF BOTANT In conceptacles of the other kind examine the numerous small sa,c-shaped cells (antheridia). At maturity the contents of each divide to form numerous very minute motile antherozoids, each with two delicate hairs or cilia. Dissect, by picking and by friction under cover-glass, a bunch of antheridia and note the branching fila- ments upon which they are borne. Make drawings to illustrate the various points of structure. 295. Number of Antherozoids required for Fertilization. —The bulk of an oosphere has been estimated equal to th
. Foundations of botany. Botany; Botany. 252 FOUKDATIONS OF BOTANT In conceptacles of the other kind examine the numerous small sa,c-shaped cells (antheridia). At maturity the contents of each divide to form numerous very minute motile antherozoids, each with two delicate hairs or cilia. Dissect, by picking and by friction under cover-glass, a bunch of antheridia and note the branching fila- ments upon which they are borne. Make drawings to illustrate the various points of structure. 295. Number of Antherozoids required for Fertilization. —The bulk of an oosphere has been estimated equal to that of thirty thousand to sixty thousand antherozoids, but apparently an oosphere may be fer- tilized by only one antherozoid. Yet a large mimber swarm around each oosphere after both have escaped from the con- ceptacles, and often their movements are so active as to cause the rotation of the oosphere. The process of fertilization may be discerned in fresh material by squeezing oospheres and antherozoids from their respective conceptacles into a drop of water on a slide. In some species, as Fucus plat^carpus (Fig. 186), antheridia and oogonia are found in the same Fig. 186.—Transverse Section of Conceptacle of a Eockweed (JW«s plaiycarpus). (x about 35.) h, hairs ; a, antheridia; o, 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 Bergen, Joseph Y. (Joseph Young), 1851-1917; Eastwood, Alice, 1859-1953. Boston, Ginn & Co.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1901
