1140 
If now we examine more closely the number 3,4 ie. the distance 
from the beginning of the last ventricle-systole before the hiatus to 
the beginning of the first auricle-systole after this, we must take 
into consideration that this includes the duration of one entire 
ventricle-period + the duration of the beginning of one ventricle- 
systole to the beginning of the following auricle-systole. The duration 
of a heart-period is 2,75 see. This subtracted from the duration of 
3,4 sec. which we found, gives 0.65 sec. If now we compare this 
number with the others of the above list we see that it is about 
'/, part of it. The cause of this short duration is in the first place 
the retardation in the conduct systems (st-a and a-v) which made 
the last ventricle-systole before the hiatus begin very late; after the 
hiatus the conduct si—a has much improved, by which the begin- 
ning of the first auricle-systole after the hiatus is anticipated. The 
co-operation of these two factors has consequently reduced the 
number we found to one third. 
The following number of the list, on the contrary, is again much 
greater; the anticipation of the first ventricle-systole after the hiatus 
is the cause of it. The number we found for the second hiatus is 
0.3 second greater than the equivalent number for the first hiatus. 
This means that now less repair of conduct takes place in the con- 
nection-systems s- than at the first falling out of a heart-period. 
After this the next following number is also again greater than 
usually. At first it seems astonishing, that this number is again as 
great (2,1 sec.) as after the first falling out. If the increase of this 
number is caused by the anticipation of the preceding systole, this 
number ought to be inferior here, for the preceding systole is here 
less anticipated than after the first hiatus. We must however not 
forget that, on account of the better conduct in the connection-systems 
the second ventricle-systole has also been a little anticipated, and 
that this anticipation is now less important than after the first hiatus. 
It appears with certainty from the measurements I made also for 
the following hiatuses, that the repair of conduct in the connection- 
systems becomes constantly worse. This is the cause that a heart- 
period must constantly sooner fall out. The fact that the repair of 
the irritability of the heart-musele constantly diminishes, and con- 
sequently the duration of the refractory period, directly after an 
hiatus, decreases less, will certainly have its influence in this respect. 
In the further progress of the curves we see indeed that the heart- 
periods fall out sooner. In this respect I made still a great number 
of measurements, for the sake of brevity L do not mention these 
here. From all these measurements the repair of conduct after the 
