CEREBRAL LOCALIZATION. 615 



results so nearly constant, that the localizations may be accepted as nearly cor- 

 rect. In the diagram (Fig. 228) and descriptions, the centres for the special 

 senses have been omitted, to be taken up in connection with the physiology 

 of olfaction, vision, audition and gustation. 



In the following description, the numbers and letters refer to Fig. 228 : 

 (1). This, which is on the precuneus (compare Fig. 222), indicates the 

 position of the centres for movements of the opposite leg and foot, such as 

 are concerned in locomotion. 



(2), (3), (4). These numbers, which are over the convolutions bounding 

 the upper extremity of the fissure of Rolando (including the paracentral 

 lobule compare Fig 222), include centres for various complex movements 

 of the arms and legs, such as are concerned in climbing, swimming, etc. 



(5) Situated at the posterior extremity of the first frontal convolution, at 

 its junction with the anterior central convolution, is the centre for the ex- 

 tension forward of the arm and hand, as in putting forth the hand to touch 

 something in front. 



(6) Situated on the anterior central convolution, just behind the upper 

 end of the posterior extremity of the second frontal convolution, is the cen- 

 tre for the movements of the hand and forearm, in which the biceps is par- 

 ticularly engaged ; viz., supination of the hand and flexion of the forearm. 



(7), (8). Just below (6), on the anterior central convolution, are centres 

 respectively for the elevators and depressors of the mouth. 



(9), (10). These numbers taken together, on the third frontal convolu- 

 tion, mark the centre for the movements of the lips and tongue, as in articu- 

 lation. " This is the region, disease of which causes aphasia, and is gener- 

 ally known as Broca's convolution." 



(11). This, which is on the lower end of the posterior central convolution, 

 marks " the centre of the platysma, retraction of the angle of the mouth." 



(12) This, which is on the posterior part of the first and second frontal 

 convolution, marks " a centre for lateral movements of the head and eyes, 

 with elevation of the eyelids and dilatation of pupil." 



(), (#), (c), (d). These letters, on nearly the whole of the posterior cen- 

 tral convolution, " indicate the centres of movement of the hand and wrist." 



The above description is quoted from Ferrier, with certain changes in 

 the nomenclature of the convolutions. Schiifer and Horsley in the main 

 have confirmed and have somewhat extended the researches of Ferrier. 

 These observers have shown that the centres on the outer surface of the 

 cerebrum, near the great longitudinal fissure, extend to the inner surface. In 

 the first frontal convolution, in front of the paracentral lobule, is a centre 

 for movements of the trunk (Tr., Fig. 229), and in front of this, is a centre 

 for the movements of the arm and shoulder. Other parts of the inner cere- 

 bral surface, except the paracentral lobule, are inexcitable. 



In man lesions of parts of the motor-cortical zone produce localized paral- 

 ysis, or what is called monoplegia, the action being crossed. " The following 

 forms of monoplegia have been observed to attend localized cortical lesions : 

 1, oculo-motor monoplegia (isolated ptosis) ; 2, facial monoplegia, sometimes 



