1145 
By measurement we can easily discover the important retardation in 
the conducting-systems between the partitions of the heart for every 
2d systole of the groups. 
In all the cases of heart-bigeminy mentioned here we have before 
us a heart, pulsating in 2 rhythms. The first systole of each group, 
which is preceded by a longer pause, is of the type of a slower rhythm, 
the Zed systole is of a quicker rhythm. Each group has one systole 
out of each of the 2 rhythms, between which the bigeminy occurs 
as a transition. 
In every bigeminus-group the first systole is wider than the 2"; 
what is wanting in the 2ed systole after the shorter pause, is added 
again to the first systole after the longer pause (law of the conser- 
vation of energy of the heart), The same relation we found in the 
velocity of the conduct in the connection-systems between the parti- 
tions of the heart for the two systoles of the bigeminusgroups. In 
my former communication I called already the attention to this fact. 
Likewise in another way I saw heart-bigeminy occur after poisoning 
with veratrine. In the still normal rhythm the conduct in the connestion- 
systems of the partitions of the heart can be alternately retarded. 
This is the origin of bigeminus-groups. Fig. 9 represents an example. 
AEANAAAAARAA A 
Fig. 9. 
The lower row of curves shows bigeminus-groups caused by alternating 
lengthening of the «-r-interval. 
In the 2"' row of curves we see every second «-v-interval retarded ; 
the auricle-systoles for these heart-periods have diminished. | found 
still a third cause for the occurrence of heart-bigeminy in the hearts 
of my frogs that were poisoned with veratrine. Up till now | found 
this sort of heart-bigeminy only once. In fig. 10 in the upper row 
we find them represented. I represented this row about 15 min. after 
the injection of 8 drops of 1°/, veratrine. Each curve of this row 
