216 General Notes. [February 
of the heart-beat must make itself felt in changing the character 
of the circulation, physiologists have recognized as of fundamental _ 
importance to the understanding of this subject, the clear com 
prehension of every physiological factor which can in any way 
modify the action of the heart. Of the reality of such modifying 
influences any one who compares his pulse rate, oberved ina 
standing and a sitting position, may be convinced. re 
searches in which he declared that when the pneumogastricnerveot | 
the nervous centers in the medulla oblongata, are electrically stimt 
lated, the pulse is slowed or the heart even brought to a complete 
standstill. Itis now one of the settled theorems of physi 
that there is in the medulla a “ cardio-inhibitory center” 
disappears so soon as both pneumogastric nerves are i 
the peck: ' 
V. Bezold and his pupils more than ten years ago demons? 
that when certain nerve branches reaching the heart from 
spinal cord through the last cervical and first thoracic 
thetic ganglia, are stimulated, the beat of the heart is quise 
Until within a few months these changes of thé rhythm o 
heart-beat were the only ones which could be definitely St 
carry from the brain to the heart of the frog impulses 
cause weakening of the contractions of the heart witho 
their rate. These relaxing fibers being bound in the så 
