336 
we should recognize a negative P-deflection, since the excitation 
wave proceeded in a retrograde direction through the auricles. 
Secondly it may be imagined that this negative deflection is gene- 
rated by a bulbus-contraction, We notice these bulbus electrograms 
Ta Ta AY 
1 co | | 
| : i & 
: 5 HEL 
a | | schi 
s i | me 
Up 
\t i 
Ke Ii EE IE / | 
j di A el i a 
a en 
ee 
Tea 
Fig. 4 
