. Botany of the living plant. Botany. FILICALES 345 of external fluid water is essential for fertilisation in Ferns. Their normal life-cycle cannot be completed without it. ,}. Fig. 286. Fertilisation in Onoclea sensibilis: the arrows indicate direction to tlic growing point. A = a vertical section through an archegonium probably within ten minutes after entrance of the first sperinatozoid. ( x 500.) i? = vertical section of the venter of an archegonium, containing spermatozoids, and the collapsed egg with a spenna- tozoid within the nucleus. Thirty minutes. ( x 1200.) (After Shaw.) The immedi
. Botany of the living plant. Botany. FILICALES 345 of external fluid water is essential for fertilisation in Ferns. Their normal life-cycle cannot be completed without it. ,}. Fig. 286. Fertilisation in Onoclea sensibilis: the arrows indicate direction to tlic growing point. A = a vertical section through an archegonium probably within ten minutes after entrance of the first sperinatozoid. ( x 500.) i? = vertical section of the venter of an archegonium, containing spermatozoids, and the collapsed egg with a spenna- tozoid within the nucleus. Thirty minutes. ( x 1200.) (After Shaw.) The immediate consequence of fertilisation is growth and segmenta- tion of the zygote, which flrst secretes a cell-wall. Jt divides into m x«-;; Fig. 287. Horizontal section of an egg, showing coiled male nucleus within the Twrlvr hours. ( X 1200.) (.\fter Shaw.) octants, four of which constitute an epibasal hemisphere, directed towards the apex of the parent thallus, giving rise to axis and leaf oi. 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 Bower, F. O. (Frederick Orpen), 1855-1948. London, Macmillan
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1919
