. Electro-physiology. Electrophysiology. 234 ELECTRO-PHYSIOLOGY CHAP. tractile substance (3). Of this the accompanying curve (Fig. 90) gives sufficient evidence. As in cardiac muscle, the striking- disparity of effect between the two directions of current immedi- ately after the injury equalises itself by degrees, and at last becomes imperceptible. The explanation here again must be sought in the independent dying of each fibre-cell. If these conclusions from the adductor muscle of Anodonta are in almost complete conformity with the polar effects of current in striated skeletal and cardiac mus
. Electro-physiology. Electrophysiology. 234 ELECTRO-PHYSIOLOGY CHAP. tractile substance (3). Of this the accompanying curve (Fig. 90) gives sufficient evidence. As in cardiac muscle, the striking- disparity of effect between the two directions of current immedi- ately after the injury equalises itself by degrees, and at last becomes imperceptible. The explanation here again must be sought in the independent dying of each fibre-cell. If these conclusions from the adductor muscle of Anodonta are in almost complete conformity with the polar effects of current in striated skeletal and cardiac muscle, this is not equally true of other parts composed of smooth fusiform cells, in which excita- tion with the constant current provokes a series of manifestations differing in many respects (at least at first sight) very widely,. FIG. 90.—Localisation of persistent closure contraction at the kathode (A") on exciting the adductor muscle of Anodonta. S=closure ; 0 = opening. and thus suggesting that the polar law of excitation may not be rigidly applicable to all kinds of muscle (31). Within the integument of Holothuria, along the entire length of the body, there is a beautiful series of longitudinal muscle- bundles, with parallel fibres, in the form of five flat bands, com- posed of solitary spindle-cells, pointed at either end, which, after the animal (H. Poll) is opened, appear as pale, or pinkish, and transparent striae. Many thinner and finer bands of circular muscle run between each two longitudinal muscle-bands, form- ing a complete investment of the body at right angles to the latter, and, like them, consisting of spindle-cells. In the muscu- lar integument, when split up lengthways, and properly stretched, ilic longitudinal muscle-bands may easily be isolated in their whole length, or in portions only, by passing a probe under one. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - colorati
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