2<S4 STUDY OF BRAINS OF SIX EMINENT SCIENTISTS AND SCHOLARS. 



demarcating the angular from the postparietal, is deep, ramified, and joins the parietal 

 at considerable depth. The upturned ends of the episylvian, the supertemporal and 

 the meditemporal, around which the three divisions of the subparietal lobule curve, 

 are well marked and extensive. 



The Ex.oGcipital and Fissured Complex. — There are two exoccipital segments ; the one 

 (eojj') of zygal shape, with its longest ramus passing near to the occipital pole, its dorso- 

 cephalic ramus joining a segment of the meditemporal ; the other (eop") corresponding 

 to the " sulcus occipitalis lateralis " of the authors, being a sinuous and much ramified 

 fissure which also joins the meditemporal segment. Its caudal terminus closely 

 approaches the postcalcarine. 



Mesial Surface. — The precuneal fissui-e may be regarded either as a zygal 

 fissure with two short caudal rami, or, more properly, as a tri-radiate fissure with 

 furcal caudal and dorsal limljs. It is independent. There are two small intrapre- 

 cuneals. 



The cuneus is marked by a large tri-radiate postcuneal, a cuneal ramus of the 

 occipital, and a vertical ramus of the calcarine. 



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

 central gyre is quite flexuous, of irregular contour, and is in general less broad than 

 its fellow on the right half. The parietal is of good width and is marked by the dis- 

 tinct transparietal. Its longitudinal extent is, however, less than most brains exhibit. 

 The paroccipital gyre is of unusual form, due to the anastomosis of the paroccipital 

 fissure with the occipital. The larger caudal portion is marked by two (postparoccip- 

 ital) fissures. 



Of the three divisions of the subparietal x'egion the angular and postparietal gyres 

 are very well developed, but the marginal is rather smaller than common. The sig- 

 nificance of this feature will be discussed in the summary. 



Mesial Surface. — The precuneus is remarkably small, as is indicated by the 

 small parietal index, 13.1. Its width, measuring between the caudal paracentral limb 

 and the occipital, is only 2.4 cm. This reduction of its size is due to the great extent 

 of the frontal lobe ; in average brains we find the caudal paracentral limlj to cut the 

 dorsi-mesal margin at a point just dorsad of the edge of the splenium of the callosum ; 

 in ('ope's brain it reaches further back by fully 1 cm. The cuneus, too, is small, l)ut 

 here the reason is a different one, depending on the closer proximity of the occipito- 

 calcarine junction to the dorsi-mesal margin. In most brains tliis junction occurs at 

 about 3.5 cm. from the margin; in Cope's brain it is 2.8 cm., bringing the point of 

 the wedge further away from the splenium. 



The callosal gyre, in its passage into the hippocampal becomes very narrow, owing 



