A NEW METHOD WITH THE BRAIN 185 



fowls, pigeons, rats, Guinea-pigs, rabbits, cats, dogs, jackals, and mon- 

 keys. 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 chloroform, and proceed 

 to catch fleas, or eat bread-and-b utter. When the animal was ex- 

 hausted, 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 con- 

 volution, 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 drawing up of the side of the face, a back- 

 ward movement of the whiskers, a turning of the head, and a contrac- 

 tion of the pupil, respectively. A similar treatment of the lower ex- 

 ternal convolution produced certain movements of the angles of the 

 mouth ; the animal opened the mouth widely, moved its tongue, and 

 uttered loud cries, or mewed in a lively way, sometimes starting up 

 and lashing its tail as if in a furious rage. The stimulation of one part 

 of this convolution caused the animal to screw up its nostrils on the 

 same side ; and, curiously enough, it is that part which gives off a 

 nerve to the nostril of the same side. 



Results much of the same character were produced by the stimula- 

 tion of the corresponding or homologous parts of the rat, the rabbit, 

 and the monkey. Acting upon the anterior part of the ascending 

 frontal convolution, the monkey was made to put forward its hand as 

 if about to grasp. Stimulation of other portions acted upon the biceps, 

 and produced a flexing of the forearm, or upon the zygomatic muscles. 

 The part that appeared to be connected with the opening of the mouth 

 and the movement of the tongue was homologous with the part af- 

 fected in man in cases of aphasia. Stimulation of the middle temporo- 

 sphenoidal convolution produced no results ; but the lower temporo- 

 sphenoidal, when acted upon, caused the monkey to shut its nostrils. 

 No result was obtained in connection with the occipital lobes. 



These experiments have an important bearing upon the diagnosis 

 in certain kinds of cerebral disease, and the exact localization of the 

 parts affected. I was able to produce epileptic convulsions of all kinds 

 in the animals experimented upon, as well as phenomena resembling 

 those of chorea or St. Vitus's dance. The experiments are also impor- 

 tant anatomically, as indicating points of great significance in reference 

 to the homology of the brain in lower animals and in man, and like- 



