General physiology; an outline of the science of life . of the an increase of cohesion between the biogen-moleculesthemselves, or between them and other constituents of the cell-body, is comprehensible when it is borne in mind that the extentof the molecular attraction is influenced by changes in the chemicalconstitution of the molecules. It has been seen above that thecohesion is diminished by the oxidation of the latter. If now theybe decomposed, the idea is strongly suggested that this profoundchange in their chemical constitution is associated with an increaseof cohesion. Upon th
General physiology; an outline of the science of life . of the an increase of cohesion between the biogen-moleculesthemselves, or between them and other constituents of the cell-body, is comprehensible when it is borne in mind that the extentof the molecular attraction is influenced by changes in the chemicalconstitution of the molecules. It has been seen above that thecohesion is diminished by the oxidation of the latter. If now theybe decomposed, the idea is strongly suggested that this profoundchange in their chemical constitution is associated with an increaseof cohesion. Upon the basis of this idea, the following picture may be drawn THE MECHANISM OF LIFE 563 of the mechanism of amoeboid protoplasmic motion. Startingfrom the spherical form of the amoeboid cell, the surface-tensionwould be locally diminished at any desired point of the peripheryby the introduction of oxygen into the biogen-molecule; theprotoplasm would be bulged out; and since new biogen-moleculeswould thus constantly come into contact with the oxygen of the. Fig. 2(30.—Various forms assumed by oil-drops in an alkaline liquid. surrounding medium, a longer or shorter pseudopodium, accordingto the peculiar character of the protoplasm, would form. Thephase of expansion would thus be mechanically explained. By theintroduction of oxygen the biogen-molecules would then havereached the maximum of their labile constitution. They wouldthen become decomposed, to a certain extent spontaneously, butmore through the action of stimuli that excite dissimilation. o o 2 564 GENERAL PHYSIOLOGY With their decomposition the surface-tension would increase, andthe stimulated protoplasm would necessarily flow back centripetally,so that the pseudopodia would be retracted—a phenomenon thatis called out in a very characteristic manner by all sorts of the phase of contraction would be mechanically their return to the central cell-body the biogen-moleculeswould have an opportunity
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Keywords: ., bookcentury1800, bookdecade1890, bookidgen, booksubjectphysiology
