STUDY OF BRAINS OF SIX EMINENT SCIENTISTS AND SCHOLARS. 281 



superficially confluent precentrals. The supercentral is fundamentally of triradiate 

 shape, though it exhibits a tendency to zygal form ; its maximum length, parallel 

 with the central, is 4 cm. The dorsal limbs embi-ace an inflected gyre, as determined 

 by the existence of a short inflected fissure. Of the two precentral segments, the 

 dorsal one {PRC, Figs. 57 and 60) extends well across the medifrontal gyre and anasto- 

 moses with the superfrontal over a vadum 5 mm. in depth. Venti'ad, over another 

 vadum of about the same depth, it joins the second precentral segment. The latter 

 [PRO", Figs. 57 and 60) joins the diagonal, and by means of this the sylvian fissure. 

 Near the dorsal end of this second precentral segment there arises a long ramus (3.5 

 cm.) which nearly traverses the entire medifrontal gyre. This corresponds to the 

 " anterior precentral " of the authors, and we thus see two precentral elements which 

 tend to run parallel with each other for a fair distance, including between them not a 

 small portion of the medifrontal. 



The transprecentral appears on the convex surface for 1.5 cm., and does not com- 

 municate with any other fissure. The diagonal fissure is short, joins the precentral as 

 described above, and anastomoses with the presylvian over a vadum. 



The superfrontal fissures does not, as is usual, spring from the supercentral, but 

 beginning in a simple manner it passes cephalad in an extremely tortuous, zig-zag 

 course, sending oft' several rami, attaining a length of 8 cm. for the principal segment. 

 Further cephalad, the fissure- may be traced a part of the distance, but in the highly 

 complex prefrontal region it is difficult to determine. Numerous transverse pieces 

 mark the superfrontal gyre. 



The medifrontal fissure is a distinctly marked segment, coursing about midway 

 between and parallel with the super- and subfrontal fissures. It has numerous rami, 

 and far cephalad it anastomoses with the prefrontal part of the superfrontal. As the 

 fissure passes toward the frontal pole, it converges toward the mesial plane, making an 

 angle of about 38° with it. 



The subfrontal fissure is practically an indej^endent one ; its main part is of Z3^gal 

 form, with an extensive dorso-cephalic ramus which reaches well toward the frontal 

 pole and by its man}' ramifications helps to make this region so very complex. 



The orbitofrontal seems to be represented by at least two well-defined segments ; 

 the mesial one traverses the frontal pole to appear on the mesial as^ject ; the lateral 

 one is triradiate. Both segments are independent. There is a long (3.7 cm.) radiate 

 fissure, independent, which marks the rather large preoperculum. 



Mesial Surface. — The supercallosal, from its junction with the paracentral to 

 its termination ventrad of the rostrum of the callosum, is an uninterrupted fissure of 

 a length of 9.5 cm., and sends off" five distinct rami into the superfrontal gyre. A short 



