78 NAOKI SUGITA 
TABLE 4 
Showing the relations of the cortical area in the sagittal section to the longitudinal 
diameter (L. F) of the cerebrum and the cortical thickness. All values for the 
fresh condition. Albino rat. 
A B (@; D E F G 
ae sna | “amc” |e] co | | 
WEIGHT ghee SAGITTAL D BRAIN 
grams mm.2 mm. mm. mm. 
I 0.161 4.4 0.52 8.5 5.6 152 
II (birth) 0.251 5.8 0.67 8.7 6.4 1.36 
III 0.358 8.3 0.90 9.2 7.4 1.24 
IV 0.432 10.1 0.99 10.2 8.0 eZ 
V 0.542 12.6 1.14 iil (0) 8.9 1.24 
VI 0.639 15.5 1.29 12.0 9.6 1.25 
NEE 0.750 Seal 1.43 12a 10.4 22 
VIII 0.841 20.1 1.48 13.6 11.0 124 
IX (10 days) 0.964 Diller 155 14.0 1G 11 Pil 
xX 1.040 Dame 1.59 14.8 12.0 LoS 
XI (20 days) eval 26.6 eae, 15) .0) 125} 1.24 
xem e253 Aol Yi is 14.9 12.8 1.16 
XIII 1335 27.6 ee 16.0 1 1228 
XIV 1.445 3 2 1.70 16.6 13.3 e25 
XV 1.554 PrS\ 57h 1.76 16e3 13330 1.19 
XVI 1.656 29.2 1 77 16.5 ital iL ey 
XVII 1.726 Bille 1.79 17.4 14.3 122, 
XVIII 1.839 32.8 1.86 17.6 14.7 1.20 
XIX 1.924 37-83 1.80 17.9 15.0 1.19 
XX 2.054 883.7 1.80 18.7 16) .8 eae 
AVera ce: (GroupsaVvi— ro)! ha Pac alo cores cise ean ene Occ eee 1.22 
Average. (GroupsecllI—XX)!* ROME oo. Solis coke stein» se see if 
as in the sagittal section though more slowly. The cortical area 
in the frontal section is a product of the cortical thickness (T’,) 
and the length of the cortex along the cerebral surface. This 
surface line of the cortex in the frontal section may be regarded 
as a part of a circle and its length may be taken as propor- 
tional to the length of the radius or the measurement W. D (the 
frontal diameter of the cerebrum), which was measured across 
the section horizontally (Sugita, 717). As shown in table 5, 
