. A manual of botany. Botany. THALLOPHTTA—FUNai V5 spherical (Micrococcus), some more elongated or rod-shaped (Bacterium), some forming a spiral (Spirillum). The multi- cellular forms are iilaments, branched or unbranohed, or small masses of cells. They are extremely polymorphic, one organism passing through several forms in its life history. Some are furnished with cilia, by which they move rapidly in the medium in which they live {fig. 828). The cells are of a very simple structure, consisting of a cell- wall enveloping a mass of protoplasm. In this is found a body capable of staining more d
. A manual of botany. Botany. THALLOPHTTA—FUNai V5 spherical (Micrococcus), some more elongated or rod-shaped (Bacterium), some forming a spiral (Spirillum). The multi- cellular forms are iilaments, branched or unbranohed, or small masses of cells. They are extremely polymorphic, one organism passing through several forms in its life history. Some are furnished with cilia, by which they move rapidly in the medium in which they live {fig. 828). The cells are of a very simple structure, consisting of a cell- wall enveloping a mass of protoplasm. In this is found a body capable of staining more deeply than the rest of the cell- contents, and hence thought to be a nucleus. The protoplasm often contains deeply staining granules, sometimes regularly disposed round the cell. The true nature of the staining. Fig. 828. k ©© 5* \ / . Fig. 828. 1. SarcinlB. 2. Bacteria. 3. Spirilla. 4. Spirillum, show- ing flagellce. {Micrococci in strings, singly and in groups. After Cohn and Sachs. (Very highly magnified.) material is, however, not yet accurately ascertained. Many of these cells contain various pigments. In the course of their life history, most of the Schizomycetes become embedded in a jelly-like substance which holds great numbers of them together. This is known as the nooglcea stage. The zoogloea may form a membrane or scum on the surface of the hquid in which the organism is living, or may occur in the shape of masses of vai-ious forms. The reproductive processes are either vegetative or asexual. In the former case the multiplication takes place with enormous rapidity by ordinary cell-division. In the second case spores are formed, one in a cell, by a process of rejuvenescence. A filament may thus give rise to a chain of spores, which ulti- mately become separate by the degeneration of the original cell-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illu
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbotany, bookyear1895
