288 STUDY OF BRAINS OF SIX EMINENT SCIENTISTS AND SCHOLARS. 



segments. The postcentral is irregularly branched and is separated from the subcen- 

 tral by a small sub-isthmus. From near the middle of the fissure springs an anasto- 

 mosing branch which joins the parietal and witli the latter marks off" a gyral "islet" 

 not unlike that seen in tlie left half of Joseph Leidy's cerebrum. The subcentral 

 fissure is moderately curved, sends ott'one ranms into the postcentral gyre and caudad 

 joins both the intermedial and the parietal. As stated before it is only superficially 

 joined by the postcentral. The transpostcentral appears on the lateral aspect as a 

 furcal fissure with its cephalic limb the longer and quite curved. 



The short parietal fissure is limited caudad by a paroccipital isthmus, and is joined 

 by the second intermedial {ITML") as well as by a short branch of the postcentral. 

 A well-marked transparietal traverses the parietal g^'re and crosses the margin to pass 

 into the precuneus. Its total length is 5.5 cm. 



The paroccipital, as was noted on the left half, also joins the occipital fissure by 

 means of its cephalic stipe. The cephalic ramus is separated from the parietal while 

 the caudal ramus joins the exoccipital. 



The intermedials are two in number (with a possible third). The first {itmV) 

 between the the marginal and angular gyres joins the subcentral ; the second {iiml") 

 joins the parietal. Another independent fissure, lying parallel to and between the 

 second intermedial and the terminus of the meditemporal might be named the " inter- 

 medialis tertius." 



The Exoccipital Fissural Complex. — The arrangement of the exoccipital segments 

 is interesting. The " occipitalis anterior " and the '' occipitalis lateralis " of the authors 

 (our cop' and eo}/' respectively) are fused into one complex, very much ramified fissure 

 which by its conjunction with the paroccipital and its close approach to the postcal- 

 carine caudad, serves to demarcate the lateral boundary of the occipital lobe with fair 

 accuracy. 



Mesial Surface. — The precuneal fissure is seen to be of quadri-radiate shape 

 and independent of neighboring fissures. The intraprecuneal piece has been described 

 as confiuent with the transparietal on the dorsum. The cuneus is marked by a tri- 

 radiate postcuneal which is almost the exact counterpart of the same fissui'e on the 

 left side. Two rami of the calcarine and two vertical independent fissures mark the 

 cuneal surface. 



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

 central gyre is a little broader and somewhat more fiexuous than the left postcentral. 

 Especially deep are the indentations by the rami of the postcentral fissure. The parietal 

 gyre is a trifle broader than the left, and of more complex appearance, particularly in 

 that region where practically a gyral " islet "' is formed. The paroccipital gyre is quite 



