. Elementary botany . L made up of cylindrical segments or compartments placed end to end. We can see a distinct separating line be- tween the ends. Each one of these segments or compartments of the thread is a cell, and the boundary wall is in the form of a cylinder with closed ends. 7. Protoplasm.—Having distinguished these parts of the plant we can look for the protoplasm. It occurs within the cells. It is colorless (, hyaline) and consequently requires close observa- tion. Near the center of the cell can be seen a rather dense granular body of an elliptical or irregular form, with its
. Elementary botany . L made up of cylindrical segments or compartments placed end to end. We can see a distinct separating line be- tween the ends. Each one of these segments or compartments of the thread is a cell, and the boundary wall is in the form of a cylinder with closed ends. 7. Protoplasm.—Having distinguished these parts of the plant we can look for the protoplasm. It occurs within the cells. It is colorless (, hyaline) and consequently requires close observa- tion. Near the center of the cell can be seen a rather dense granular body of an elliptical or irregular form, with its long diameter transverse to the axis of the cell in some species; or trian- gular, or quadrate in others. This is the nucleus. Around the nucleus is a granular layer from which delicate threads of a shiny granular substance radiate in a starlike manner, and terminate in the chlorophyll band at one of the pyrenoids. A granular layer of the same substance lines the inside of the cell wall, and can be seen through the microscope if it is properly focussed. This granular substance in the cell is protoplasm. 8. Cell-sap in spirogyra.—The greater part of the interior space of the cell, that between the radiating strands of protoplasm, is occupied by a watery fluid, the " ; 9. Reaction of protoplasm to certain reagents. —We can employ certain tests to demonstrate that this granular substance which we have seen is protoplasm, for it has been found, by repeated experiments with a great many kinds of plants, that protoplasm gives a definite reaction in re- sponse to treatment with certain substances called reagents. Let us mount a few threads of the spirogyra in a drop of a solution of iodine, and observe the Thread of spiro- gyra, showing long cells, chlorophyll band, nucleus, strands of proto- plasm, and the granular wall layer of protoplasm
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Keywords: ., bookcentury1800, bookdecade1890, bookpublisher, booksubjectbotany
