CHANGES IN HUMAN CEREBELLUM WITH AGE 23 



the tissues during dehydration and embedding, so that I have 

 been able to determine the number of cells in similar fractional 

 parts of each cerebellum. These fractional parts have been 

 called equivalent unit areas and designated by EUxV. 



In this study I have confined my cell counts to two areas in 

 each hemisphere: first, the area anterior to the primary sulcus, 

 and, second, the area anterior to the great horizontal sulcus, or 

 areas 1 and 3, respectively, as shown in figure 2 of my earlier 

 paper, which is here repeated as figure 1. 



Cell counts were made for the four areas, two on the right and 

 two on the left, in each case and the sections were also studied in 



order to estimate the extent to which cells had actually been lost. 

 This is necessary because it is not possible to tell from the num- 

 ber alone whether cells have been lost or are congenitally absent. 



After completing the counts I tabulated the results according 

 to age, sex, and color; I have compared the results of the counts 

 for ordinary white males of presumably average intelligence 

 with counts made on white males of superior intelligence; and 

 I have compared also the results for the right and left hemi- 

 spheres. 



As far as my data go, the counts for eleven ordinary white 

 males show no significant difference when compared with the 

 counts for negro males. Neither does any difference appear 

 when the results for the ordinary white males are compared with 

 the results for five white males of superior intelligence. I have 



