CRANIO-CKIIEBRAL TOPOnL'APHY 10S9 



664) runs up^vards fcr al-ent an inch just l.cl.in.l tli.- termination of tlic con-nal 

 suture, or two nHlu'S bchnul the extornal angular \mHv^^. T.. indicate the ti^-ur.' 

 of ►"^.yjvms, a hne should l.e (h-awn from a point corresix.nrlinf: to the i.terion 

 (p. 1081, fig. 6o9) backwards, at tirst gently and th.-n more al.ruptlv up- 

 wards, to one three-(iuarters of an inch helow the j.arietal eminence ' The 

 ascending limb will start from a point two inches behind and slightly above tlie 

 external angular process, and more oblitiuelv forwards and uj.wards for al>out an 

 mch. 



Fissure of Rolando.— This most important fissure, around which the ux.tor 

 area is grouped, runs downwards and forwards, separatinu the frontal and parietal 

 lobes between the following points: The upper end of the Hssure, the upper 

 Rolandic point, will be found about half an inch behind the centre of the sagittal 



Fio. 6Go.— Drawixg of a Cast of the Head of ax Adii.t Mai.k. 

 (Prepared by Professor Cuuniugham to illustrate crauio-cere))ral topograpliy. ) 



FissrjiE nr 



ROLASVO 



POSITION OF 

 FRONTAL EMINENCE 



mini) LP. 



TEMPIiHAL 

 FlaSCHll 



line Tp. lOOO") — a line drawn from just below the glabella to the external occijiital 

 protuberance. On the skull, this upj>er Rolandic jmint will be nearly tw.. inches 

 behind the bregma. The lower extremity of the fissure, inferior Rolandic point, 

 would be about half an inch above the Sylvian line and one inch Ixhind the 

 Sylvian point (fig. 666). Owing to the obiicpiity of the fissure of Rolandi.. thi.s 

 lower point will be nearer tin- ciinmal suture than the uppei-. being distaiU fn>m it 

 about «)ue inch. A lin(> drawn between the ujiper and lower Hnlandic ])oints (the 

 Rolandic line) will give the direction of the fissure of Rolando with sufficient accu- 

 racy, when the two genua, the upper c<tncave and the lower convex fonvards (fig. 

 664) are allowed for. The Rolandic line forms with the sagittal line an angle 

 anteriorly of 6o° to 70°; if jtrohmged downwards and f<»rwards t<» the zvgoma, the 

 line would reach this process about its centre (Le Fort;. 

 60 



