. General physiology; an outline of the science of life. 420 GENERAL PHYSIOLOGY poles of the body are stimulated in opposite senses, the anodic to contract, their motion being stronger in the direction of the posterior end, and the kathodic to expand, the motion of these being stronger in the direction of the anterior end, in whatever relation to the direction of the current the body may be fixed (Fig. 202, G). Hence in Amceba, as in Faramceoium, the making of the current produces at the two poles ojjposite effects, leading to contraction at the anode and to expansion at the kathode. But, in r
. General physiology; an outline of the science of life. 420 GENERAL PHYSIOLOGY poles of the body are stimulated in opposite senses, the anodic to contract, their motion being stronger in the direction of the posterior end, and the kathodic to expand, the motion of these being stronger in the direction of the anterior end, in whatever relation to the direction of the current the body may be fixed (Fig. 202, G). Hence in Amceba, as in Faramceoium, the making of the current produces at the two poles ojjposite effects, leading to contraction at the anode and to expansion at the kathode. But, in reality, the polar effects of the galvanic current on muscle, as the later researches of Biedermann ('90, 1, 2) on smooth and cross-striated muscles have shown, are more complex than the law of excitation of muscle, in the form in which it has thus far been expressed, declares. The conception of excitation has hitherto been limited to the augmentation of these processes that in. Fig. 201.—Ai/Kxbaproteus. At the left an unstimulated individual possessing numerous pseudo- podia ; at the right two individuals stimulated by the galvanic current. At the anode a typical contraction is shown, at the kathode a strong expansion ; this is noticed especially clearly upon sudden reversal of the direction of the current. contractile substances find their expression in contraction. Ex- pansion (relaxation) has customarily been regarded as a phenom- enon of depression. This is incorrect. By depression is meant a diminution or complete cessation of the vital processes in question, as is exemplified by narcosis. Expansion, however, is based upon an augmentation of processes, just as is contraction. The confound- ing of expansion and depression leads to false ideas. The two con- ceptions should be sharply separated, and the term excitation should be extended to include the augmentation of those processes that in contractile substances find their expression in expansion. From Biedermann's resear
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