128 Journal of Comparative Neurology. 



table iii. 



The Percentage Reduction for each Lobe in the Number of Cells in 

 Unit Column for the Sides and Bottom of the Sulci. 



The average number of cells per (square millimeter) col- 

 umn in the sunken portion of each lobe is then found by re- 

 ducing the average number of cells in the exposed surface (Ta- 

 ble II) by the the average percentage reduction for the lobe 

 (Table III). The averages for the sunken surfaces appear only 

 incidentally in Table IV. 



H. Now that the area in square millimeters of the ex- 

 posed and of the sunken surfaces of each lobe has been found, 

 and also the average number of cells per square millimeter col- 

 umn in the exposed and in the sunken areas of each lobe, a 

 multiplication of these two numbers gives the absolute number 

 of cells for any particular exposed or sunken surface, and the 

 sum of all these products gives the total number of cells in 



the entire cortex. 



TABLE IV. 



The Total Number of Functional Nerve Cells in the Cerebral 



Cortex. 



