. Class-book of botany : being outlines of the structure, physiology and classification of plants : with a flora of the United States and Canada. Botany; Botany; Botany. 150 first expands into a proper cell, and is usually attached to the wall of the sac near the micropyle. It then di- vides itself transversely, becoming two cells; the upper tiongates either with or without subdivision, forming a filament (snspensor); the lower cell enlarges by subdi- vision, first spherically, and afterwards the little mass begins to take form according to the species, showing cotyledons, plum
. Class-book of botany : being outlines of the structure, physiology and classification of plants : with a flora of the United States and Canada. Botany; Botany; Botany. 150 first expands into a proper cell, and is usually attached to the wall of the sac near the micropyle. It then di- vides itself transversely, becoming two cells; the upper tiongates either with or without subdivision, forming a filament (snspensor); the lower cell enlarges by subdi- vision, first spherically, and afterwards the little mass begins to take form according to the species, showing cotyledons, plumule, etc, until fully developed into the embryo. 759. Schleiden's view. Owing to the ex- treme difficulty of observation in this minute field, different views of this process have been advanced. That of Schleiden should not be overlooked. He maintains that the end of the pollen tube actually penetrates the sac and itself becomes the embryonic cell. The pollen grain is in this view the primitive cell, and is itself quickened into development by the contents of nbryo sac. 760. Fertilization IN THE CONIFERS. 60S. Growth of tlie eml rro In Hippuris vulgaris. The ferti- lised cell has divided itsell In to several, of which c, b, con stitute the - Where no stvle or stigma exists, as in the Coni- to the apex of the sac; a, em- f ^ ,jcn feUa Jirectly jnto the micropvl,. bryo dividing into •_>. then into l • * - 4 ceiia. of the naked ovule and its tubes settle into th« tissue of the nucleus. 761. Chemical changes in germina- tion. The ovule matures with the com- pletion of the embryo, and passes into the fixed state of the in which the embryo sle • ' r tube, r, raphe; c, chalaza; o, prinnne; solution which shall contain the proper a, secundine; n, nucleus: a, sac which materials for cell-formation or growth ; the tube appears to have penetrated. that is, gluten and other nitrogenous matters, oil, starch, etc., are to be changed to diastase, the same as yeast, and dextrin
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectbotany, bookyear1861
