STRYCHNIA-STIMULATION OF VENTEICLE. 597 



normal heart, but also in the maximum, and often far into 

 relaxation. After the phase has passed the stage of reduplica- 



FiG. 186. 



Stimulation of Ventricle (submaximal), 



tion ensues. Eeduplication is very complete; its latency 

 becomes diminished as diastole advances. The reduplicated 

 ventricular beat is succeeded by an auricular pulsation. After 

 the customary pause, the heart resumes its wonted rhythm. It 

 is rarely that stimulation falling at the commencement of 

 ventricular systole causes inhibition. If the auricle is un- 

 stimulated and its rhythm is unaltered, there is short latency 

 for the ventricular reduplication. If the auricle is stimulated 

 and contracts before the ventricle, there is long latency, but the 

 latter is rarely seen when a refractory phase is present. 



Ventricular Stimulation — Maximal Stimuli. 



In this case no refractory period exists. An inhibitory period 

 exists occasionally, but with this exception, all stimulations pro- 

 duce reduplication (Fig. 187). Should stimulation fall at the 



Fig. 187. 



Stimulation of Ventricle (maximal). 



commencement of systole, the latency is long, nearly equal to 



the length of the beat ; and the reduplication is very complete. 



Stimulation at the maximum of systole has a latency of about 



