GROWTH OF THE CEREBRAL CORTEX 105 
TABLE 11 
Showing relations between the cortical area in the sagittal section and the sagittal 
diameter of the cerebrum (L. F). Colwmn E gives the relative lengths of the long 
side when the area is reduced to.a rectangle with the short side equal to the cortical 
thickness. These values have almost a fixed ratio to the sagittal diameter of the 
cerebrum (L. F) in each group, the average being 1.20. For the explanation see 
the text 
A B Cc ED E E G 
CORTICAL CORTICAL 
BRAIN WEIGHT BRAIN AREA IN | THICKNESS Cc L.F E 
GROUP WEIGHT SAGITTAL IN SAGITTAL D F 
SECTION SECTION 
grams m m2 mm. mm. mm. 
N XI 1.163 24.0 1.61 14.9 Tee 22, 
N XII 
N XIII 1.369 Diao) 1783 15.9 eel 1LPAl 
N XIV 1.430 29.2 1.84 15.9 13.2 1 all 
N XV I 5RY/ 28 .4 1.82 15.6 (3e5 1.16 
N XVI 1.629 30.5 1.88 16.2 13.6 1.19 
N XVII 1.739 31.8 1.94 16.4 13.9 1.18 
N XVIII 1.829 33.0 1.93 ffi 14.3 120 
N XIX 1.972 33.8 1.97 Nie? 14.6 1.18 
N XX 2.052 33.8 1.92 17.6 14.7 iL ile 
N XXxI PD AN 35.0 1.99 17.6 15) sal sles 
N XXII 
N XXIII 2.345 30 1.86 19.2 15eo 1 2A: 
Average (Groups) N XIN Xxexlil). 2.5. eae - Pe eee Hon a Ay 1.20 
ACV ETA Mey (GO US IN ENOL MING EROXG) tate yi ncic ete eee eraih Gpetett coleoia a1 Se EN 1.19 
to 1.00 or on the average 0.97 for Groups N XI-N XXI, so 
that the cortical area in the frontal section may be obtained by 
the following formula, in which 7’, denotes the average cortical 
thickness in the frontal section: 
Wa Dee TS COSGu (W. D and T;,, in millimeters) 
For Groups N XIII-N XX, the coefficient is 0.98 (table 13). 
The corresponding coefficient in the Albino, Groups XIII-XX, 
is about 0.93, as shown in table 5. Comparing the absolute 
values of the cortical area in the frontal sections in two forms of 
like brain weight group (Groups N XIII-N XX to Groups 
XIJI-XX), we find that in the Norway it is on the average 
larger by about 10 per cent (table 12). 
