from The Century Dictionary and Cyclopedia
- n. The substance, resembling neuroglia, which supports the so-called “primitive tubules” or subdivisions of nerve-fiber containing hyaloplasm.
- n. The supporting framework of the cell protoplasm, inclosing in its reticulum the hyaloplasm.
- n. In entomology, the longitudinal and radiating filaments in the muscle-fiber of an arthropod.
Sorry, no etymologies found.
The fibrils are usually arranged in a network or reticulum, to which the term spongioplasm is applied, the clear substance in the meshes being termed hyaloplasm.
The yolk comprises (1) the cytoplasm of the ordinary animal cell with its spongioplasm and hyaloplasm; this is frequently termed the formative yolk; (2) the nutritive yolk or deutoplasm, which consists of numerous rounded granules of fatty and albuminoid substances imbedded in the cytoplasm.
In muscle there is the same thing, viz., a framework of spongioplasm staining with hematoxylinthe substance of the sarcous elementand this encloses a clear hyaloplasm, the clear substance of the sarcomere, which resists staining with this reagent.
In an ameboid cell, there is a framework of spongioplasm, which stains with hematoxylin and similar reagents, enclosing in its meshes a clear substance, hyaloplasm, which will not stain with these reagents.
During contraction of the musclei. e., stimulationthis clear substance passes into the pores of the spongioplasm; while during extension of the musclei. e., when there is no stimulationit tends to pass out of the spongioplasm.
Under stimulation the hyaloplasm passes into the pores of the spongioplasm; without stimulation it tends to pass out as in the formation of pseudopodia.
The former is probably of the same nature as the hyaloplasm of the cell, but the latter, which forms also the wall of the nucleus, differs from the spongioplasm of the cell substance.
The relative amounts of spongioplasm and hyaloplasm also vary in different cells, the latter preponderating in the young cell and the former increasing at the expense of the hyaloplasm as the cell grows.
The size and shape of the meshes of the spongioplasm vary in different cells and in different parts of the same cell.
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