HEART-MUSCLE 



499 



current, send a make-shock of galvanism through the muscle. At the 

 cathodal end of each compartment of the muscle a faint contraction will 

 be seen. Open the key, and a slight contraction will be seen at each 

 anode. The muscle as a whole has no general contraction. This 



FIG. 278 



Sarcolemma 



The contraction- wave in cross-striated muscle (Cassida equestris). The beginning of the con- 

 traction-wave of shortening and thickening is seen at the left in thick black lines. (Rollet via 

 Szymonowicz and MacCallum.) 



condition suggests the facts as regards the number of physiological anodes 

 and cathodes in any part of the body, e.g., a man's arm when stimulated 

 through the skin. Subsidiary anodes and cathodes then clinically are 

 apt to be numerous and must be allowed for. 



VII. HEART-MUSCLE. 



Expt. 61. The Stannius Ligatures. (Apparatus: Kymograph, etc., 

 heart-lever, frog-board, needle and thread, inductorium.) (Cardiograph.) 

 (A) The First Ligature. Having pithed a large frog and fastened 

 it to the frog-board, open slightly the thorax and expose the heart by 

 opening the pericardium. Cut the connective tissue from beneath, lift 



