STUDY OF BRAINS OF SIX EMINENT SCIENTISTS AND SCHOLARS. 249 



directly dorsad of the episylvian ramus there occurs an anastomosis of three fissures, 

 viz. : the subcentral, parietal, and intermedial. The gyre between the parietal and 

 subcentral dips below the general surface as it passes caudad, and by means of the 

 indenting ramus near its end has the appearance of a dimple, or cortical islet, from 

 which radiate a number of fissural rami. The appearance is a very unusual one, and 

 is best seen in Fig. 24. 



The paroccipital is notable for the length and direction of its zygon or stem. 

 This is 3.5 cm. in length, and converges towards the median line cephalad, instead of 

 being parallel to or converging toward this plane caudally, as is seen in ordinary 

 brains. Rudinger describes a similar feature in the brain of Justus v. Liebig, where 

 the redundancy of the paroccipital gyre is apparently so great as to push the correspond- 

 ing fissure far laterad. In Leidy's case it is the caudal arm of the paroccipital gyre 

 which is immensely developed, and hence the caudo-lateral deviation of the main 

 course of the fissure. The cephalic paroccipital stipe is short and passes near the 

 occipital ; the cephalic ramus bifurcates to embrace the parietal, and the mesial limb 

 anastomoses with a transparietal piece. The caudal ramus and stipe together form a 

 T-shaped ending* passing parallel with the ventro-lateral border of the hemicerebrum, 

 instead of approximately vertical to it, as is the rule. 



Between the episylvian and the terminal portion of the supertemporal lies an 

 intermedial fissure of more complex arrangement than is common. It is irregularly 

 zygal in shape and one of its rami anastomoses deeply at the site of the subcentral- 

 parietal junction. 



The fissuration in the occipito-temj^oral transition is so intricate in this case that 

 in the present state of our knowledge concerning the interpretation of these fissures 

 no definite statements can be made. It is to be hoped that further studies may help 

 to elucidate some of the problems presented here. 



Mesial Surface. — The precuneal fissure is of the usual zygal shape with a short 

 stem or zygon running parallel with the callosal fissure. The cephalic rami are both 

 long ; the dorsal one reaching the dorsi-mesal margin. A short intraprecuneal lies 

 dorsad. 



The adoccipital fissure, marking off a cuneolus has been described on page 246. 

 The cuneus is quite intricately marked by three fissural segments, one of which passes 

 well onto the convex surface in the redundant arm of the paroccipital gyre. 



Gyres of the Parietal and Occipital Lobes (Lateral Surface). — The post- 

 central gyre is unusually massive, particularly in its middle and ventral portions. It 



* Called by Eckke the " transverse occipital," and supposed by him to represent a part of the "AfEenspalte " ; see, 

 however, the writer's paper, "The Fissural Integrality of the Paroccipital," 1900. 



