264 



THE CIRCULATION OF THE BLOOD 



A. Normal 



B. Apex cooled 



C. Apex warmed 



Fig. 84. Records of electrocardiogram and movement of ventricle of frog showing that when 

 the apex is warmed a typical T-wave appears in place of a wave in the opposite direction appear- 

 ing when the apex is cooled. (From Mines.) 



