543 
may be expected, therefore, that the experiment succeeds better 
during a postcompensatory systole. This may be seen from fig. 1, 
in which the auricles received a fresh stimulus during the post- 
Fig. 1. 
Fig. 2. 
compensatory systole at the second upward deflection of the signal, 
and hereafter followed another extrapause of the ventricle, which 
was not preceded by a premature ventricular systole. 
At 2 the auricles were again stimulated at the commence- 
35* 
