242 Scientific Inielligence. 
I operated on nearly a hundred animals of all classes—fish, frogs, 
fowls, pigeons, rats, guinea pigs, rabbits, cats, dogs, jackals, and 
monkeys. The plan was to remove the skull, and keep the animal 
in a state of comparative insensibility by chloroform. So little 
was the operation felt that I have known a monkey, with one side 
of the skull removed, awake out of the state induced by the chlo- 
roform, and proceed to catch fleas or eat bread and butter. When 
the animal was exhausted I sometimes gave it a little refreshment, 
which it took in the midst of the experiments. : 
First, as to the experiments on cats, I found that on applying 
the electrode to a portion of the superior external convolution the 
animal lifted its shoulder and paw (on the opposite side to that 
stimulated) as if about to walk forward; stimulating other parts 
of the same convolution, it brought the paw suddenly back, or put 
out its foot as if to grasp something, or brought forward its hind 
leg as if about to walk, or held back its head as if astonished, or 
turned it on one side as if looking at something, according to the 
particular part stimulated. The actions produced by stimulating 
the various parts of the middle external convolution were a draw- 
ing up of the side of the face, a backward movement of the whis- 
kers, a turning of the head, and a contraction of the pupil respec- 
tively. A similar treatment of the lower external convolution pro- 
duced certain movements of the angles of the mouth; the animal 
Aas 
to the nostril of the same si 
