of Edinburgh, Session 1884 - 85 . 
325 
respond on stimulation, had more blood beneath it in the cavity of 
the auricle, and it was also still moist on its outer surface. 
Between 11.47 a.m. and 1.25 p.m. the left auricle was stimulated 
seventeen times, a contraction following each stimulus. In one 
instance, at 12.43, two strong contractions followed a single 
stimulus. 
At 1.28, on slightly distending the right auricle by squeezing 
blood into and from the ventricle, contraction was obtained on 
stimulating any point, each contraction being circumscribed. At 
1.38 contractions were fainter, and not obtainable at every point. 
At 1.40, after fully distending the auricle, a very marked con- 
traction followed, and extended along the whole inner border of 
the auricle. 
At 1.50 a similar but less extensive contraction was obtained in 
the same way. 
At 1.5 stimulation of the distended auricle produced a double 
contraction along its border, and strong but circumscribed contrac- 
tions at several other points. 
At 2. 1 the empty auricle was stimulated, but without response. 
On distending the cavity, contractions at several points were 
obtained on stimulation. 
At 2.6 the auricle was distended, and on stimulation some feeble 
contractions were obtainable, but only at a few points. The 
heart was immersed in water at 100° Fahr. for about one minute. 
On stimulation there was no response. The organ was next 
immersed in cold water (about 50° Fahr.), but no contractions could 
be obtained. 
Summary . — Spontaneous contractions in left auricle for 47 
minutes. Contractions could be induced in it on stimulation of 
right 4 minutes after this. It responded to direct stimulation for 
exactly 3 hours from the time the animal was killed. The right 
auricle continued to beat spontaneously for 54 minutes. It 
responded to stimulation for 3 hours and 41 minutes. 
In another heart obtained at the same time, which was not 
otherwise examined, fibrillary contraction of the muscular wall of 
the right ventricle, near the auriculo-ventricular groove, wms 
observed half an hour after death. 
It seemed to us that this long continued contractility of the mam- 
