. The essentials of botany. Botany. 126 BOTANY. pastry, etc. (Mucor mucedo), is as follows: The vertical hyphse, which are filled with protoplasm, become enlarged at the top, and in each a transverse partition forms (A., a, Fig. 58), the portion above the partition (J) becomes larger, and, at the same time, the transverse partition arches up (B, a), finally appearing like an extension of the hypha, then called the columella {C, a). The protoplasm in the enlarged terminal cell {b) divides into a large number of minute masses, each of which surrounds itself with a cell-. Fio. B8.—Diagrams showin
. The essentials of botany. Botany. 126 BOTANY. pastry, etc. (Mucor mucedo), is as follows: The vertical hyphse, which are filled with protoplasm, become enlarged at the top, and in each a transverse partition forms (A., a, Fig. 58), the portion above the partition (J) becomes larger, and, at the same time, the transverse partition arches up (B, a), finally appearing like an extension of the hypha, then called the columella {C, a). The protoplasm in the enlarged terminal cell {b) divides into a large number of minute masses, each of which surrounds itself with a cell-. Fio. B8.—Diagrams showing mode of growth of the spore-case of Mucor mu- cedo. A, very young stage; B, somewhat later; C, spore-case with ripe spores. a in all the figures represents the partition-wall between the last cell of the fila- ment and the spore-case, b. wall; these little cells are the spores, and the large mother- cell is now a spore-case, or sporangium. 266. The spores are set free in different ways: in some cases the wall of the spore-case is entirely absorbed by the time the spores are mature; in other cases only portions of the wall are absorbed, producing fissures of various kinds. The spores germinate readily when on or in a substance capable of nourishing them, by sending out one or two hyphse, which soon branch and give rise to a mycelium. Spores may, if kept dry, retain their vitality for months. 267. Sexual reproduction takes place after the produc- tion of asexual spores. Two hyphsB, in the air or within. 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 Bessey, Charles E. (Charles Edwin), 1845-1915. New York, Holt
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1884
