1599 
Fig. 12. 
twice as rapid one, and the latter again to the halved rhythm. 
After the preceding remarks the explanation of this fact is obvious. 
A short remark about the a—v-interval may still follow here. In 
my third communication about the heart-rhythm I have already 
shown experimentally, that the a—v-interval consists of 2 parts viz.: 
L. Time of conduction along the systems of connection, 
2. period of latent stimulation of the ventricle. 
The experiments described before give again an entire affirmation 
of this fact. If namely I can convert the halved ventriele-rhythm into 
the normal one, by an induction stroke, it is certain that during the 
halved rhythm after every auricle-systole the “Erregung” reached the 
ventricle, but every 2ed systole recoiled, because the ventricle was 
then refractory. We find now during the halved rhythm the a-v-interval 
shorter than during the normal one. The cause of this cannot be 
found in a difference in the times of conduction along the systems 
of connection. For in both rhythms the stimulation after every 
auricle-systole is conducted along these systems. The shorter a-v- 
interval consequently originates in the fact, that in this rhythm the 
duration of the latent stimulation is shorter than during the normal 
twice as rapid rhythm. After the longer pauses of the halved rhythm 
the duration of the latent stimulation is consequently abbreviated. 
The bigeminusgroups also distinctly explain this question. With 
these every normal physiological “Erregung” is conducted to the 
ventricle, for I can convert these groups into the normal ventricle- 
rhythm. The a-v-interval before the 2"¢ systole however is considerably 
longer than that before the first systole. Here this difference is likewise 
caused by the difference of duration of the stage of the latent stimulation. 
LITERATURE. 
1. Boru, Studien über Herzgifte. Würzburg 1871 
2, A. von Bezorp und L. Hirt, Ueber die physiologischen Wirkungen des 
