292 STUDY OF BRAINS OF SIX EMINENT SCIENTISTS AND SCHOLARS. 



tions of form consist in a flattening and lengthening together with an irregular reduc- 

 tion of the lateral diameters of the cerebrum. 



In consistency the brain is only moderately firm and does not admit of much 

 handling. The main cerebral arteries are atheromatous. There are no signs of gyral 

 atrophy. 



The callosum shares in the undue lengthening of the cerebrum, being 8.0 cm. 

 long. At the genu its thickness is 10 mm., the average thickness of the body is 5 

 mm., while the maximum thickness of the splenium is 11 mm. 



Left Hemicerebrum. The Interlobar Fissures. The Sylvian Fissure and its 

 Rami. — The length of the sylvian fissure is 5.7 cm. Its course is nearly straight and 

 its walls are in close apposition. The sylvian angle is approximately 20°. Its depths 

 are as follows : Pre-sylvian 9 mm.; medi-sylvian, 15 mm., post-sylvian, 27 mm.* The 

 presylvian ramus is furcal. The reason for interpreting the arrangement here as a 

 bifurcated presylvian rather than a conjunction of a subsylvian with the presylvian is 

 that the radiate fissure in the usual arrangement lies within the preoperculum 

 embraced b}^ the sub- and presylvian rami. A subsylvian ramus is not pi-esent. The 

 episylvian is 1.5 cm. in length. The hyposylvian is short and superficially confluent 

 with a supertemporal segment. 



The central fissure is 10.5 cm. in length, quite sinuous and of a good depth through- 

 out. There is no anastomosis with any neighboring fissure. 



The occipital fissure is very deep, shows numerous interdigitating suljgyres, is 4 

 cm. in length on the meson and 2.5 cm. on the dorsum. It meets thecalcarine fissure 

 at an obtuse angle owing to the abutment of a spur from the precuneal-hippocampal 

 junction. 



The calcarine fissure is quite tortuous and runs uninterruptedly into the tri-radiate 

 postcalcarine. The occipito-calcarine stem is 2.5 cm. in length. 



Fissures of fJte Frontal Lobe {Lateral Surface). The Precentral Fissural Complex. 

 — The supercentral is irregularly zygal and gives off the superfrontal cephalad. The 

 precentral proper anastomoses with the superfrontal, the subfrontal and, via the short 

 transprecentral, the sylvian fissure as well. 



The superfrontal attains a length of 8 cm. The medifrontal springs from the 

 orbitofrontal and is 4 cm. in length. The subfrontal is irregularly zygal, its stem 

 being 3 cm. in length. The radiate fissure is independent and 3.5 cm. in length. 



Mesal Surface. — The supercallosal fissure is separated from the paracentral, sends 

 off two distinct rami across the superfrontal gyi'e near the frontal pole and is 10.5 cm. 

 in length. A medicallosal fissure, 3.5 cm. long, marks the callosal gyre. The para- 



* These depths are practically useless owing to the great distortion suffered by this specimen. 



