282 STUDY OF BRAINS OF SIX EMINENT SCIENTISTS AND SCHOLARS. 



parallel fissure, which may be conveniently called the medicallosal, marks the callosal 

 gyre just dorsad of the genu of the callosum. 



The paracentral fissure is of the usual form, the stem being 4 cm. in length ; the 

 cephalic limb 1.4 cm.; the caudal limb 1.3 cm. on the meson, and 1.7 cm. on the 

 dorsum. There is a short inflected fissure appearing on both the dorsal as well as the 

 mesial aspect, and situated, as is the rule, caudad of the cephalic paracentral limb. 



In the superfrontal gyre there is a very short frontomarginal segment confluent 

 with one of the rami of the supercallosal. The rostral fissure is distinct, 4.7 cm. in 

 length and independent; the subrostral is merely indicated by a slight furrow. 



Orbital Surface. — There are two orbital fissures separated from each other by 

 a shallow vadum ; the mesial one is of zygal shape, the lateral one quadri-radiate, 

 resembling the letter " K." The olfactory fissure is simple and attains a length of 3.8 

 cm. The cephalic end becomes visible on the mesial aspect. 



Gyres of the Frontal Lobe (Lateral Surface). — The precentral gyre of this 

 half is slightly less massive, and of rather less tortuous configuration than its fellow 

 on the right side. The ventral portion is the broader. The superfrontal gyre is of 

 good width throughout and beside the numerous indentations of the exceedingly 

 ramified superfrontal, is richly supplied with smaller fissures, notably in the prefrontal 

 portion, and generally of transverse direction. The medifrontal gyre is broad, par- 

 ticularly in the caudal portion where the well-marked "anterior precentral" has 

 already been noted. The intricate fissuration in the prefrontal region gives this part 

 of the gyre a very complex appearance, and it is difficult to trace the fundamental 

 fissural pattern here. The existence of a fairly long medifrontal fissure divides the 

 gyre into two tiers. The subfrontal gyre is the one to which the massiveness of the 

 left as compared with right frontal lobe is due. The great width of the medifrontal 

 gyre would seem to apparently diminish the area of the subfrontal, but this is more 

 than compensated for by its greater longitudinal expanse. Measurements taken from 

 the ventral end of the central (or any other point of general constancy) to various 

 corresponding points in the subfrontal gyre of the two sides shows that of the left to 

 be considerably larger than the right in practically all its dimensions. The greater 

 massiveness of the left subfrontal is readily appreciated when the two hemicerebra are 

 compared with each other. 



Mesial Surface. — The superfrontal, on its mesial surface, appears as a broad, 

 richly-fissured gyre, of a width ranging between 2.9 cm. and 2.1 cm., and giving an 

 impression of redundancy ; few brains show quite so much cortical expanse in thig 

 region. The paracentral gyre is of good size and bold contour ; its length is about 

 4 cm., its width between 2 and 2.7 cm. Its dorsi-mesal margin is indented by the cen- 



