559 
enlarged postcompensatory systole again the ventricle-alternation arises. 
The curves of fig. 5 were taken about 1 minute after those of 
fig. 4. A short time before the alternation had been elicited experi- 
mentally. It still exists at the commencement of the figure. 
i 
sa 
= 
= 
=> 
= on 
S= 
= 
Ss 
= 
=, 
= 
= 
Fig. 4. 
Fig. 5. 
| 
5 
VAA A AAA 
At the first deflection of the signal the auricles are incited to an 
extrasystole by an induction shock in the beginning of a large ven- 
tricalar systole. After this extrasystole the excitation reaches the 
ventricle during the refractory stage, so that no ventricular systole 
follows; an extra pause of a ventricle does follow, however. After 
this extrapause the first ventricular systole is enlarged again, so 
36* 
