238 STUDY OF BRAINS OF SIX EMINENT SCIENTISTS AND SCHOLARS. 



vertical to this assumed horizontal plane passes through the most cephalic point of the 

 cerebrum. From this cephalic plane horizontal distances are measured to various 

 points and are converted into centesimals of the cerebral length. Various mechanical 

 aids may be employed to determine these distances with accuracy. With the aid of a 

 stereograph, ordi nates were drawn from the selected points to; the horizontal line and 

 the abscissae thus obtained were directly measured. These values were verified by 

 further measurements upon the sj^ecimen itself with sliding compasses, the hemicere- 

 brum being placed on a graduated plane similar to Mathieu's instrument. The sub- 

 sequent conversion of these figures into centesimals of the hemicerebral length allows 

 of comparison with other brains, no matter what their size or what the degree of 

 shrinkage may be so long as there is no actual distortion. 



The horizontal distances which have been recorded in the brains here studied are 



as follows : 



Lateral Surface. 



From the cephalic point to 



1. Tip of temporal lobe. 



2. Junction of sylvian and presylvian fissures. 



3. Ventral end of central fissure. 



4. Junction of sylvian and episylvian fissures. 



5. Caudal point. 



Mesal Surface. 

 From the cephalic point to 



6. Cephalic edge of callosum. 



7. Porta (Foramen of Monro). 



8. Dorsal end of central fissure. 



9. Dorsal intersection of paracentral fissure. 



10. Caudal edge of callosum. 



1 1 . Occipito-calcarine junction. 



12. Dorsal intersection of occipital fissure. 



The measurements of the cerebellum and pons are practically restricted to the 

 principal diameters. 



Unless otherwise mentioned, the length of a fissure was obtained by laying a wet 

 string along its course. The fissural depths were determined by means of a flat sound 

 with smooth rounded end and graduated in millimeters. 



In the description of the fissures and gyres the author enployed the following 

 schema in order to secure an orderly manner of treatment for all the brains : 

 The interlobar fissures : 



