ON THE CEREBELLUM. 
575 
The Experimenis of M. Fleuretis on the Brain.—Effects of re¬ 
moval of Farts of the Brain. —M. Fieurens has instituted a con¬ 
nected course of experiments on the functions of the brain, the 
result of which is, to a certain extent, satisfactory. He laid bare 
a portion of the brain, and he began by pricking the hemispheres ; 
there was no muscular contraction—no symptom of pain. He 
cut off a portion of one of the hemispheres in an horizontal di¬ 
rection ; still no contraction—no pain. The animal seemed to 
be unconscious of the affair. He cut yet deeper and deeper; 
the animal evinced no sign of suffering. At length he reached 
the medullary part—he removed the corpora striata, and the op¬ 
tic thalami, and yet there was no pain. This, gentlemen, will 
not, perhaps, appear incredible, if you recollect that although, 
according to our opinion, the hemispheres of the brain are the 
organs to which impressions on the sensitive nerves are con¬ 
veyed, and where they are received and we are rendered con¬ 
scious of certain sensations, it is only through the medium of the 
nerves that this is effected, and there are no nerves in the portions 
which we have pricked or removed. Cut off in any part nervous 
communication, and you destroy sensation ; and so here there is 
no feeling of pain, for there is no nerve to give notice of injury. 
He ventured deeper—he pricked the corpora quadrigemina, and 
then crying, and trembling, and convulsions, ensued; and these 
• increased as he penetrated deeper still into the medulla ob¬ 
longata' :—the senses of sight and hearing were destroyed, and 
stupor stole over the animal, and he was incapable of voluntary 
motion. 
Effects of Pressure. —Pressure was made on the hemispheres 
laterally. No effect was produced, the animal was altogether 
unconscious of it. Pressure was then made vertically, and in¬ 
sensibility speedily ensued—not, however, total insensibility, 
for there remained a faint dull sensation; and the animal, when 
violently excited, could be roused to the performance of certain 
actions—the quadruped could walk if pushed along, and the bird 
could fly when thrown in the air. Professor Mayo says, that 
‘Mf a section be carried through the striated portion of the cor¬ 
pus striatum, the animal will spring forwards, and continue to 
advance in a straight line till it meets an obstacle, when it still 
preserves the attitude of one advancing.” 
Experiments on the Cerehellum. —M. Fieurens next pricked 
the cerebellum—there was neither muscular contraction nor pain ; 
he cut off portions of it, but the animal did not appear to be 
aware of the injuiy. When, however, a deeper incision was 
made, when the experimenter cut far into the trunk of the arbor 
vitsD, there was strangely irregular action of some portion of the 
