Electro-physiology . electrophysiolog02bied Year: 1896-98 278 ELECTRO-PHYSIOLOGY CHAP. excitation) usually coincides with the beginning of the katelectro- tonic variation, and is inseparable from it. From these experiments, as well as from the earlier observa- tions of Tschirjew, it would appear that the entrance of the katelectrotonic current at the point of leading off docs not coincide in time with the closure of the polarising current, and that the underlying alteration of the nerve diffuses more slowly than the wave, of excitation which precedes it. This separation of the two apices is o
Electro-physiology . electrophysiolog02bied Year: 1896-98 278 ELECTRO-PHYSIOLOGY CHAP. excitation) usually coincides with the beginning of the katelectro- tonic variation, and is inseparable from it. From these experiments, as well as from the earlier observa- tions of Tschirjew, it would appear that the entrance of the katelectrotonic current at the point of leading off docs not coincide in time with the closure of the polarising current, and that the underlying alteration of the nerve diffuses more slowly than the wave, of excitation which precedes it. This separation of the two apices is only seen distinctly when the tract of nerve led off is sufficiently remote from the polarised tract, since both FIG. 211. processes appear to begin simultaneously at the kathode, at the moment of closure, and, according to Bernstein's view, can only be separated after further propagation. The absolute rate at which the katelectrotonic alteration is transmitted can there- fore hardly be determined exactly from such experiments. Bernstein estimates it at about 9—10 in. per sec. The develop- ment and diffusion of galvanic anelectrotonus is shown by the same method to be essentially similar, when the excitation by the rheotome is effected (by reason of the led-off transverse- section of the nerve) with ascending currents. Even with strong currents there is invariably a much smaller negative initial varia- tion (excitatory wave) than with descending excitation, along with which there is a positive anelectrotonic deflection increasing
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