340 



Lee 



Signal 



Signal. 



Signal. 



fiG. 2.— Isolated rabbit's heart perfused with Ringer's solution by the method of Langendorfl'. 



A shows the effect of injecting into the lateral tube 2 c.c. 1 per cent, pyridine ; B, injection Of 2 c c 



1 per cent, collidine ; C, injection of 2 c.c. 1 per cent, nicotine. Time, 1 cm. =10 seconds. 



i 



