ACTION OF THE EXCISED MAMMALIAN HEART. 
227 
Tracing 9. 
Wave of contraction in ventricle of Cat’s heart, 30 minutes post mortem; taken by double cardiograph ; 
mechanical stimulation near the base gives a ventricular contraction, in which the lever resting on 
the base commences to rise earlier than the lever resting near the apex; mechanical stimulation near 
the apex causes the lever near the apex to rise before the lever near the base. 
Tracing 10. 
Wave of contraction in a strip cut obliquely from the right ventricle of a Dog, 10 minutes post mortem. 
Mechanical stimulation. The proximal lever is raised before the distal lever. 
Tracing 11. 
//c< 
Wave of contraction in right auricle of Dog’s heart. Upper line base, lower line apex. Excitation 
near base (/l). Ditto. Excitation near apex (a). 
2 G 2 
