1087 
At half past 2 o'clock L injected the frog 8 drops 1 °/, veratrine 
into the abdominal cavity; at LO minutes to three there was halving 
of rhythm, the electrogram shows a very quick R-top. In the fol- 
lowing reproductions at 3 o'clock, 10 min. past, half past 3 and a 
quarter to four, the R-top remains unsplit, but at every reproduction 
it becomes wider. The duration of the R-top is in the last repro- 
duction 1*/, time-unity of */, second. In the following three repro- 
ductions at 5 minutes, 20 minutes, and half past 4 o’eloek the duration 
is L*/,, 2 and almost 3 time-unities. 
With the increase of the duration of the R the splitting becomes 
more conspicuous after every reproduction. The reproduction of half 
past four o’clock is represented here in fig. 9. By this the formation 
of the splitting of the R-branch becomes obvious. By the slackening 
of the transmission of stimulation the influence of the apexnegativity 
comes constantly somewhat later (this influence is after all the cause 
of the decline of R). At last this influence comes so late, that the 
basisnegativity after the quick original oscillation increases again 
before the tonical slow oscillation of T. 
By the next reproduction, which I made at 4.40, this connection 
becomes still more conspicuous. For this purpose I had amply 
cauterized the point of the heart with a red-hot probe. With a, for 
the rest equal, deduction (auricle-heartpoint) I obtained now the 
reproduction Fig. 10. 
Here I see indeed again the same initial top. This explains the 
splitting of the top. The cause of it is to be found in the slackening 
of the transmission of stimulation and the manner in which the 
heart-muscle contracts. 
At the same time we can see in these experiments an experi- 
mental proof that the two components, in the interference of 
which the detinitive electrogram originates (at diphasical deduction) 
consist of a quick initial oscillation and a subsequent slow one. Accord- 
ing to SAMOJLOFF, who saw likewise in his monophasical ventricle- 
curves the initial top, this would originate, beeause the deduction 
could never be obtained purely monophasically; he supposed the 
curves still to be partially diphasieal, which would be the origin 
of the sharp initiai top. In my curves, however, the initial top is 
detected before the influence of the apex-negativity is felt. The 
part of the ventricle-curve into which the sharp initial top falls is 
consequenily purely monophasical. In the hearts of my frogs that 
were poiscned with veratrine, I always found this split R-top; it is 
however no special consequence of the effect of the veratrine, but 
wheresoever slackening of the transmission of stimulation takes place 
