1596 
rhythm. This appears distinctly from Fig. 2 and 3. This diminution 
is likewise apparent in Fig. 7. 
Fig. 7. 
Here I applied to a frog’s heart, pulsating after the poisoning in 
the balved rhythm, an extra-stimulation (at f) at the end of the 
diastole, the consequence of which was an extra-systole. The next 
following systole and further the first systoles of the bigeminus- 
groups are then visibly reduced. After two minutes this bigeminy 
spontaneously changes into the halved rhythm. If now a little earlier 
in the diastole, I cause an extra-systole, (vide Fig. 8 at f) the 
ee EE 
Fig. 8. 
following systole is not sufficiently reduced to obtain bigeminus and 
the halved rhythm continues. But at the same time the extrasystole 
is not little enough to restore the normal rhythm. 
2. Extra-stimulation of the basis ventriculi. 
As in these series of experiments the stimulant was placed near 
the atrio-ventricular-limit, the results deviate somewhat from those 
that have been described above. I shall illustrate this by a few 
examples. In Fig. 9 I have caused at 1 an extra-pause without 
