100 



CEREBRAL LOCALIZATION. 



results, as concisely stated by Raimey, may be 

 briefly summarized as follows : 



1. The cortex is capable of artificial stimula- 

 tion, and the functions of certain areas may 

 thus be accurately determined. 2. A well-de- 

 fined relation exists between the cortex and 

 certain muscular groups. 3. The excitable re- 

 gion of the cortex, where motor effects are 

 chiefly produced, may be said to be localized 

 in the following parts, some of which may be 

 seen by reference to the figure: The center 



movements of the forearm and hands (6) ; for 

 extension and forward movement of the arm 

 and hand (5) ; centers for complex movements 

 of the arms and legs when acting together (2, 

 3, 4). The ascending parietal convolution pre- 

 sents, from above downward, four centers for 

 complex movements of the hand and wrist (a, 

 &, c, d), such as the use of individual fingers, 

 etc. The superior parietal convolution pre- 

 sents the center which presides over the move- 

 ments of the leg and foot, as in the act of 



Pro. 2. SAME VIEW OF THE HTTMAN BEATW, SHOWING THE AREAS OF THE CEREBRAL CONVOLUTIONS. (After Ferrier.) 

 1 (on the postero-parietal [superior parietal] lobule), advance of the opposite hind-limb as in walking; 2, 3, 4 (around the 

 upper extremity of the fissure of Rolando), complex movements of the opposite leg and arm, and of the trunk, as in 

 swimming ; o, "ft, c, d (on the postero-parietal [posterior central] convolution), individual and combined movements 

 of the fingers and wrist of the opposite hand : prehensile movements ; 5 (at the posterior extremity of the superior 

 frontal convolution), extension forward of the opposite arm and hand ; 6 (on the upper part of the antero-parietal or as- 

 cending frontal [anterior central] convolution), supination and flexion of the opposite forearm ; 1 (on the median portion 

 of the same convolution), retraction and elevation of the opposite angle of the mouth by means of the zygomatic muscles; 

 8 (lower down on the same convolution), elevation of the ala nasi and upper lip with depression of the lower lip, on the 

 opposite side; 9, 10 (at the inferior extremity of the same convolution. Broca's convolution), opening of the mouth with 

 9, protrusion, and 10, retraction of the tongue region of aphasia, bilateral action ; 11 (between 10 and the inferior ex- 



, , 



side ; 12 (on the posterior portions of the superior and middle frontal convolutions), the eyes open widely, the pupils 

 dilate, and the head and eyes turn toward the opposite side; 13, 13 (on the supra-marginal lobule and angular gyrus), 

 the eyes move toward the opposite side with an upward 13, or downward 13- deviation ; the pupils generally contracted 

 (center of vision) ; 14 (of the infra-marginal, or superior [first] temporo-sphenoidal convolution), pricking of the opposite 

 ear, the head and eyes turn to the opposite side, and the pupils dilate largely (center of hearing). Ferrier, moreover, 

 places the centers of taste and smell at the extremity of the temporo-sphenoidal lobe, and that of touch in the gyrus 

 uncin-itus and hippocampus major. 



for movements of the lips and tongue lies at 

 the base of the third frontal convolution, near 

 the fissure of Silvius (9 and 10 on figure). On 

 the first and second frontal convolutions there 

 is a center (12) for lateral movements of the 

 head, for elevation of the eyelids, and for dila- 

 tation of the pupil. The ascending frontal 

 convolution presents, from below upward, the 

 following centers: for elevation and depres- 

 sion of the corners of the mouth (8 and 7) ; for 



walking. The sensory region of the cortex is 

 confined to the parietal, temporal, and occipital 

 lobes of the cerebrum. In it certain centers 

 have been definitely located by Terrier which 

 are not as yet accepted as fully proved. 



It may be asked whether these facts, which 

 have resulted from physiological experiment 

 and from faradization, are of any practical 

 value at the bedside. Their value may easily 

 be shown. In a case of brain-disease, where 



