. Practical botany, structural and systematic, the latter portion being an analytical key to the wild flowering plants, trees, shrubs, ordinary herbs, sedges and grasses of the northern and middle United States east of the Mississippi. Botany. 64 PBACTICAL BOTANY. the vesicle within, more enlarged). The materials of this vesicle are taken from the cytohlast, which consists of globular atoms, contained in the sac. The embryonic vesicle resembles all other new cells. Let us trace its development after fertilization in one or more ovules of an oxogen. After attaining a certain size, the vesicle d
. Practical botany, structural and systematic, the latter portion being an analytical key to the wild flowering plants, trees, shrubs, ordinary herbs, sedges and grasses of the northern and middle United States east of the Mississippi. Botany. 64 PBACTICAL BOTANY. the vesicle within, more enlarged). The materials of this vesicle are taken from the cytohlast, which consists of globular atoms, contained in the sac. The embryonic vesicle resembles all other new cells. Let us trace its development after fertilization in one or more ovules of an oxogen. After attaining a certain size, the vesicle divides by a cross-partition into two cells (Cut XII., Fig. 3), and the lower of these into another pair (Fig. 4). One cell of this pair continues the process of division in two directions (Fig. 5), and the resulting cells do the same, until the mass of cells assumes the out- line of a rudimentary embryo, its upper extremity repre- senting the radicle, in form nearly cylindrical, and its lower extremity the cotyledons under the form of a notch (Fig. 6). Gradual changes in the aspect of this embryo are shown in Figs. 7 and 8 and 9. Tlie figures are, of course, all magnified. In the Asclepiads, the masses of cohering pollen-grains, dislodged in due time from their anther-cells and brought near the base of the stigma, pro- duce a great many tubes, which penetrate the base of the stigma (Fig. 10). The fertilization of the naked ovules of the Gymnosperms usually leads to the pro- duction of several embryos, which, however, are com- monly all but one Cut Xn. 8. 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 Koehler, August. New York, H. Holt and Company
Size: 1963px × 1272px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1876
