260 STUDY OF BRAIN8 OF SIX EMINENT SCIENTISTS AND SCHOLARS. 



Left Hemicerebrum. The Intcrlohar Fissures. The Sylvian Fissure and its Earai. 

 — Tlie length of the sylvian fissure from its presylvian junction to the episylvian is 

 4.8 cm. The sylvian angle is 20°. The depths are as follows : Presylvian, 12 mm.: 

 medi-sylvian, 18 mm.; post-sylvian, 31 mm. The presylvian ramus is 2 cm. in 

 length. There is no subsylvian ramus present. Caudad the sylvian terminates in an 

 episylvian with but slight change in direction and a hyposylvian ramus anastomoses 

 with the supertemporal fissure. 



The Central Fissiio-e. — The length of the central fissure is 10.5 cm., or 1 cm. longer 

 than that of the right as well as much more sinuous and more ramified. A slight 

 vadum separates it from the supercentral. 



The Occipital Fissure. — The length on the meson is 3.5 cm.; on the convex sur- 

 face, 1.5 cm. The fissure is quite deep and the interdigitating subgyres are well 

 marked. Near the dorsi-mesal margin it is joined by a small tri-radiate adoccipital. 

 As in the brain of Joseph Leidy the occipital fissure makes an angle of about 50° with 

 our horizontal plane. 



The Calcarine Fissure. — The calcarine and postcalcarine elements join to form an 

 uninterrupted fissure of moderately sinuous course. Its total length is 5.2 cm. The 

 occipito-calcarine stem is 2 cm. in length. 



Fissures of the Frontal Lobe {Lateral Surface). The Precevtral Fis.'^ural Complex. — 

 The supercentral fissure is of the usual zygal shape, anastomosing cephalad with the 

 superfrontal. INIeasuring along the full extent of the dorsal and ventral limbs the 

 fissure has a length of 6.5 cm. The precentral is quite tortuous and ramified. It 

 anastomo.ses over a vadum with the diagonal and transprecentral elements which in 

 this specimen are so closely crowded as to appear practically merged. 



The superfrontal fissure is represented by two well-marked segments. Two para- 

 mesial pieces, one quite small, mark the superfrontal gyre. In the prefrontal I'egion 

 transverse fissu ration prevails. 



The medifrontal fissure is chai'acterized by marked tortuosity and numerous 

 ramifications ; its extent is quite considerable. The subfrontal is a rather short but 

 toi-tuous fissure quite independent of all neighboring fissures. There is one distinct 

 orbitofrontal segment. 



Mesal Surface. — The supercallosal sweeps cephalad uninterruptedly from its junc- 

 tion with the paracentral for 7 cm., terminating just cephalad of the genu (callosi). 

 The paracentral is of simple form and average extent. There is an independent intra- 

 paracentral piece, but no inflected fissure. The frontomarginal segments are very well 

 marked ; there are three distinct pieces of which the cephalic one anastomoses with the 

 rastral fissure. The rostral is 4 cm. in length ; there is also a shorter subrostral. 



