A treatise on the nervous diseases of children, for physicians and students . grees with the median line. Several instru-ments (the author has used Wilsons cyrtometer) have been constructed, of ahorizontal and a vertical strip of metal, joining each other at this angle. Thevertical strip can be so adjusted as to cover the fissure of Rolando, and if thevertical strip is of the same length as the central fissure (about three and ahalf inches), a division into three equal parts will give the three chief divisionsof the motor area, each area extending about an inch to each side of thecentral fissu
A treatise on the nervous diseases of children, for physicians and students . grees with the median line. Several instru-ments (the author has used Wilsons cyrtometer) have been constructed, of ahorizontal and a vertical strip of metal, joining each other at this angle. Thevertical strip can be so adjusted as to cover the fissure of Rolando, and if thevertical strip is of the same length as the central fissure (about three and ahalf inches), a division into three equal parts will give the three chief divisionsof the motor area, each area extending about an inch to each side of thecentral fissure. The fissure of Sylvius—the lower boundary of the motorarea—can be mapped out as follows : Draw a line from the lower margin of ANATOMY AND PHYSIOLOGY OF THE BRAIN. 449 the orbit to the auditory meatus. Draw a second line parallel to the first,from the external angular process of the frontal bone, and let it extend backone inch and a quarter. This is the first point. From the parietal emi-nence draw a perpendicular line to the base line ; on this line, three-fourths. Fig. 122.—Diagrams representing the Localization of Cortical Centres. (Dana.) Thoseassigned to the frontal lobes the author considers doubtful; also the distribution ofmotor centres on the median surface beyond the paracentral lobule. of an inch below the eminence, note point two. A line joining these twopoints indicates the position of the fissure of Sylvius. This fissure is aboutfour inches long. If we prolong the line of the fissure of Sylvius to the me-dian line we get the position of the parieto-occipital fissure at the junction of29 450 THE -VEATOCS DISEASES OF CHILDREX. the two lines. Most of the centres can be located with reference to thesethree fissures. (For some further details see chapter on Abscess, followingEar Disease.) In locating the motor areas the author has been in the habit of verifyingthe correctness of these lines by making an electrical test (with a weak fara-dic current and using
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectnervous, bookyear1895
