Thompson, Cells in the Cerebral Cortex of Man. 123 



*Note. — The small fractions which appear in this table are due to the pres- 

 ence of scattered large pyramidal cells in the regions in which they occur. They 

 might be disregarded without appreciable error, in calculating the number of 

 cells in the cortex but they represent cells of such large size that it is necess»ry 

 to retain them in calculating the volume of the cells for the various regions. 



Table I gives the unit columns for each region, while the 

 details of the process of computing them are recorded in Ta- 

 ble VII. 



C. In order that the regions of the cortex which have 

 similar functions might be placed together in the tables for pur- 

 poses of comparison, Flechsig's' division of the cortex into 

 sensory regions, motor regions, and association regions, was 

 adopted. All the motor regions are grouped together and all 

 the sensory regions, while the two great association regions, an- 

 terior and posterior, are placed in separate columns. Hammar- 

 berg's division into structural regions does not coincide in detail 

 with the functional regions marked out by Flechsig. Region 3, 

 for instance, the lateral surface of the second frontal gyrus (as 

 distinguished from the orbital surface) is, in Hammarberg's sub- 

 division of the cortex, a single region. According to Flechsig, 

 a portion of the posterior part belongs to the motor region, 

 while the remainder of it belongs to the anterior association re- 

 gion. The same is true of structural region 4. Wherever this 

 occurs, the structural region has been placed in the functional 

 region to which the greater part of it belongs. The discrepancy 



1 Flechsig: Gehirn und Seele. 2te. Ausgabe. Leipzig, 1896. Flechsig uses 

 the term, association-center, but in English terminology, center has been used 

 to indicate a much more limited cortical area to which a definite function can 

 be assigned. W^e have, therefore, adopted the word region, instead of center. 



