parts of these animals, the very parts supplied by
this portion of the spinal marrow continued.
M. Flourens omits to inform us by what means
he judged of the continuance of the circulation.
The following experiment, whilst it confirms that
of M. Flourens in its results, supplies this deficiency.
At a quarter to four o’clock, the lower portion
of the spinal marrow in a frog, from the third
vertebra inclusive, was destroyed by a fine wire.
The breathing continued. At a quarter to six,
the circulation in the web still continued good.
The wire was now passed upwards, so as to destroy
the medulla oblongata and brain. The
respiration ceased immediately. The circulation
very gradually declined, the arteries became pulsatory,
then much larger, and like the veins,
except for the direction of the globules. The
capillaries next began to become less numerous,
some disappearing. The breadth of the arteries
became quite extraordinary. The nerves and
arteries became much alike, and equally pale and
slow. As the immediate effect of the shock, the
arteries became small, and one became impervious,
for a short time, to the blood. It gradually
recovered.
At ten minutes after seven o’clock, a very fine
wire was passed from the part of the medulla
covered by the spinous process of the third vertebra,
to the bottom of the spinal canal and withdrawn
towards one side. The respiration and the circulation
in the web were unaltered. The wire was then
introduced again and moved about in every direction
until there was no longer any spasmodic
motion of the limbs. The respiration and circulation
still continued perfect. At eleven o’clock
these functions still continued good. At eight
o’clock in the following morning, and at the
same hour in the evening, twenty-four hours
after the destruction of the spinal marrow, the
respiration and circulation still continued good.
This experiment does not succeed equally well
with the eel. At half-after nine o’clock, a fine
wire was passed into the spinal canal of an eel,
just below the medulla oblongata, and downwards
so as to destroy the spinal marrow. The circulation
in the tail was immediately enfeebled; the
beat of the caudal ventricle ceased, the respiratory
acts continued. At eleven o’clock all circulation
in the tail had disappeared, but that of the
pectoral fin, and the acts of respiration con