80 NAOKI SUGITA 
TABLE 5 
Showing, in columns ‘A to E, the relations of the cortical area in the frontal section 
to the frontal diameter of the cerebrum (W. D) and the cortical thickness, and, 
in columns H to J, the relations of the total area of the frontal section and the 
frontal diameter of the cerebrum. All values for the fresh condition. Albino rat. 
A B Cc D 1D) F G H I J 
vcat | “CAL W.D pei fis 
5 TWAIN |) RULES MEE | cn E or |SQUARE| H 
sche THOS ee [ears | 2 aimee a a es ae WD i 
seers Sacrton SEEEION 
grams mm. mm. mm. mm. mm.2 mm. 
i 0.161; 3.9} 0.56} 7.0] 6.6] 1.06 | 11.9! 43.6) 0.27 
II (birth) Q.251| 5-7 -| 0.78 |) e723)| ~ 7. 79) 01954) 720) a5 9es eee 
Ill 0.358} 8.0) 1.02 | 7.9) 8.7 | 0.91 | 20.6 | 75.7) 0.27 
IV Or432)" OF i Lew | 8.21} 9.3 | 0.88 | 22:4 | 86.5) 0.26 
V 0.542) 11.7 | 1.33 | 8.7 | 10.1 | 0.86 | 26.9 | 102.0) 0.26 
VI 0.639) 14.4] 1.55 | 9.3 | 10.6 | 0.88 | 31.1 | 112.4] 0.28 
VII 0.750; 16.4 | 1.7 9.5 | 11.2 | 0.85 | 32.6 |. 125.4) 0.26 
VIII 0.841) 18.4:| 1.82 | 10.1 | 11.6 | 0.87 | 3819 | 134-6)50:29 
IX(10 days) | 0.964) 20.4 | 1.86 | 11.0 | 12.1 | 0.91 | 42.3 | 146.4] 0.28 
x 1.040) 20.8 | 1.82 | 11.4 | 12.4 | 0.92 | 44.2 | 153.8) 0.29 
XI eudays) LV70) 21.7) 191-| 11245) 12:7 | O90.) 4527 16h. 30228 
XII 1.253) 23.0 | 1.91 | 12.0 | 13.0 | 0.92 | 47.2 | 169.0) 0.28 
XIII 1.335) 23.2 | 1.94 | 12.0 | 138.2 | 0.91 | 50.2 | 174.2' 0.29 
XIV 1.445) 24.8 | 1.99 | 12.5 | 13.4 | 0.93 | 52.3 | 179.6) 0.29 
XV 1.554) 24.3 | 1.97 | 12.3 | 13.5 | 0.91 | 54.0 | 182.3] 0.30 
XVI 1,656) 24.3°| 1.94 | 12.5 | 1327)90.91 | 54.9) 187 sn 90228 
XVII 1.726] 24.6 | 1.90 | 12.9 | 13.8 | 0.94 | 56.4 | 190.4) 0.30 
XVIII 1.839] 26.0 | 1.97 | 13.2 | 14.1] 0.94 | 58.9 | 198.8] 0.30 
XIX 1.924) 24.8 | 1.83 | 18.5 | 14.3 | 0.94 | 57.0 | 204.5) 0.28 
XX 2.054 24.9 1.72 | 14.5 | 14.6 | 0.99 | 63.4 | 213.2) 0.30 
Aversce (Groups iV §) 5435009 Lie ee ee ee 0.91 0.28 
Average (Groups atl XX) fe i see ee eee 0.93 
the increase in the frontal diameter being retarded relative to 
the sagittal diameter in brains weighing more than 1.4 grams 
(Sugita, 717). 
If, as given in columns H. and JI, table 5, the area of the total 
frontal section is compared with the square of W.D of the cor- 
responding brain group, the above inference will be supported 
by the fact that the ratio, given in column J of the same table, 
