1874.] Localization of Function in the Brain. 231 



The occipital lobes do not react on stimulation. Destruction of these 

 lobes caused no loss of sensation or voluntary motion, but an apparent 

 abolition of the instincts of self-preservation. 



The corpora striata are shown to be motor in function, and the optic 

 thalami sensory. 



Stimulation of the corpora quadrigemina causes dilatation of the 

 pupils, opisthotonic contractions, and the utterance of peculiar cries 

 when the testes alone are irritated. The nature and signification of these 

 phenomena are regarded as still obscure, and requiring further investi- 

 gation. 



Some experiments have been made on the cerebellum of monkeys. 

 They confirm the author's previous views as to the relation of this organ 

 to coordination of the optic axes, and the maintenance of bodily equili- 

 brium. The experiments are not detailed, as they will form the subject 

 of a future paper. 



New experiments on dogs essentially confirm those already published, 

 while many new facts have been elicited. Those on jackals agree in the 

 main with the experiments on dogs, both as to the character of the results 

 and the localization of the centres. New experiments on cats generally 

 confirm, as well as further define, the results described by the author in 

 his former paper. The facts of experiment on rabbits, guineapigs, and 

 rats are essentially alike, and also confirm former statements. 



In all those animals the sensory regions are defined and their position 

 compared with those in the brain of the monkey. 



The only result obtained by stimulation of the cerebral hemispheres 

 in pigeons was contraction of the pupil. The region associated with this 

 action, situated in the postero-parietal aspect, is compared with a similar 

 region in the mammalian brain, and regarded as the seat of visual per- 

 ception. 



Movements of the limbs in frogs, and of the tail and fins in fishes (as 

 in swimming), can be excited from the cerebral hemispheres in these 

 animals. Exact localization of motor and sensory centres is not possible. 



The optic lobes in birds, frogs, and fishes seem related to movements 

 of flight and progression, in addition to their relation with the eyes. 

 Similar phenomena result from irritation of the cerebellum; but the 

 signification_of these is reserved for future inquiry. 



From the data of physiological experiment a- foundation is obtained 

 for constructing an anatomical homology of the convolutions. 



Among other points in homology the fissure of Eolando is shown to 

 be the homologue of the crucial sulcus in the brain of the Garni vora. 



The whole brain is regarded as divided into sensory and motor regions, 

 corresponding to the anatomical relation of these regions to the optic tha- 

 lami and corpora striata and the sensory and motor tracts. 



The motor regions are regarded as essential for the execution of 

 voluntary movements, and as the seat of a corresponding motor memory 



