. Text-book of botany, morphological and physiological. Botany. 55* PHANEROGAMS. consist of one or more closed chambers in which the ovules are formed ; the lower, hollow, swollen part of. each separate seed-chamber which encloses the ovules is called the Ovary; the place or the mass of tissue from which the ovules spring directly into the ovary is a Placenta. Above the ovary the seed-vessel narrows into one or more thin stalk-like structures or Styles, which bear the Stigmas ; these are glandular swellings or expansions of various forms which retain the pollen that is carried to them, and by
. Text-book of botany, morphological and physiological. Botany. 55* PHANEROGAMS. consist of one or more closed chambers in which the ovules are formed ; the lower, hollow, swollen part of. each separate seed-chamber which encloses the ovules is called the Ovary; the place or the mass of tissue from which the ovules spring directly into the ovary is a Placenta. Above the ovary the seed-vessel narrows into one or more thin stalk-like structures or Styles, which bear the Stigmas ; these are glandular swellings or expansions of various forms which retain the pollen that is carried to them, and by means of the moisture which is excreted from them induce the emission of the FIG. 382.— Butomus umbellatus: A flower (natural size); B the gymeceum (magnified), the perianth and stamens removed, n the stigmas; C horizontal section through three of the monocarpellary ovaries, each carpel bearing on its inside a number of ovules ; D a young ovule ; E an ovule immediately before fertilisation, t i the integuments, K the nucellus, A'5the raphe, etn the embryo-sac; F horizontal section through the stiginatic portion of a carpel (strongly magnified), pollen-grains attached to the stignmtic hairs; G horizontal section of a quadrilocular anther, but the valves z are so separated at P that it then appears bilocular; //part of an anther-lobe (corresponding to j8 in G),y the point where it has become detached from the connective, e the epidermis, x the fibrous layer of cells (endothecium) ; / diagram of the entire flower; the perianth pp consists of two alternate whorls of three leaves, as also does the andrcecium, but the stamens of the outer whorl /"are double, those of the inner whorl/' simple and thicker; the gynseceum also consists of two whorls of three carpels, an outer c and an inner whorl c'\ there are therefore six alternate whorls of three, the members of the first staminal whorl being doubled. The Gynseceum is always the final structure of the flower. Whe
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1882
