321 
was applied later. Not a single exception to this did I find in a 
large number of experiments with more than 100 frogs. 
While fibrillation of the ventricle could be generated only by one 
induction-shock at the very commencement of the excitable period, l 
movarwbly obtained a fully co-ordinated extrasystole, when the stimulus 
was applied at a later stage of the excitable period with the same 
force and at the same spot. 
To the brief delirium, originating at 4 after the extra-stimulus I 
shall revert lower down. 
Fig. 2 shows that during an experiment the metabolic condition 
of the ventricular muscle must deteriorate considerably before delirium 
can be brought about. In the upper row a stimulus was twice 
administered to the base of the ventricle 15 minutes after the bleeding 
(at | in the beginning, at 2 in the middle of the descending branch 
of the 7-deflection). In both cases a complete extra-systole of the 
ventricle appeared. The second row of curves was registered a quarter 
of an hour after the bleeding and now at 3a little before the middle 
of the descending branch of the 7-deflection an extra stimulus is given 
to the base of the ventricle. Although the stimulus was now applied 
later than at 1, ventricular fibrillation now follows. Now that the 
general condition of the ventricular muscle is grown worse in a 
quarter of an hour, the stimulus on the ventricle must be applied 
still later to generate an extra-systole. It is obvious that the electric 
deflections are again very irregular. Shortly after this registration 
this fibrillation stopped spontaneously. When a few minutes after- 
wards I applied again a stimulus to the ventricle, a permanent 
fibrillation of the ventricle ensued, which | registered for 14 hours 
(see Fig. 3). I regret that the commencement of the fibrillation was 
not registered. The top curves were photographed 5 minutes after 
the beginning of the delirium. We see that now the deflections, as 
in fig. 2, are irregular. The 2°¢ row was registered */, hour after 
the commencement of the fibrillation. Now the curves present a 
totally different aspect. A certain regularity in the deflections 
can be observed. Every time three smaller deflections occur between 
two larger ones, but each of four successive deflections is different 
from the others and the tempo is irregular. But these groups of 4 
deflections recur continually. The bottom curves were taken 14 hours 
after the commencement of the fibrillation. Though the deflections 
are slightly altered the regularity of the delirium remains. In both 
registrations the two successive, equal deflections are at the same 
distance from each other. In the suspension-curves the regular 
deflections of the auricular contractions may be observed (in the 
