84 NAOKI SUGITA 
TABLE 6 
Giving for each brain weight group the average brain weight, ratio in cerebral volume, 
computed cortical volume and the data used to obtain the computed cortical volume, 
and ratio in cortical volume 
A B C D E F G 
L.F X 
BRAIN WEIGHT GROUP ; ae LF W.D Tf} W. DXeie pp aasanea 
eater vonume aa ee “Contra ‘vous: youu 
CEREBRUM ance Conn CORTEX 
grams mim. mm. mm. mm 3 
I 0.161 5.6 6.6 0.54 19.96 
II (birth) 0.251 1.00 6.4 ool 0.73 35.97 1.00 
Ill 0.358 | 1.34 a: 8.7 0.96 61.81 Lae 
IV 0.452 1.66 8.0 9.3 1.10 81.84 2.28 
V 0.542 22 ee) |) UO al 1.24 111.46 3.10 
VI 0.639 ZOD 9.6 10.6 1.42 144.50 4.02 
VII 0.750 Sez, 10.4 IN 1.58 184.04 9.12 
VIII 0.841 3250): 11.0 16 1.65 210.54 5.85 
IX (10 days) 0.964 4.04 11.6 Wall eg 240.02 6.67 
x 1.040 4.10 12.0 12.4 172 255 . 94 mee 
XI (20 days) all | Zeal 12.5 12.7 1.82 288 .93 8.03 
XII 1.253 4.80 12.8 13.0 1.83 304.51 8.47 
XTil 1.335 dba 13.0 13.2 1.83 314.03 8.73 
XIV 1.445 5.40 13.3 13.4 1.85 | 329.71 9.17 
XV 1.554 5.89 13).7 13.5 1.87 345.86 9.62 
xXVI 1.656 6.05 14.1 Bie 7 1.86 | 359.30 | 9.99 
XVII 1.726 | 6.44 14.3 13.8 1.85 365.08 | 10.15 
XVITI 1.839 | 6.72 14.7 14.1 1.92 | 397.96 | 11.06 
XIX 1.924 6.9 15.0 14.3 1.82 | 390.39 | 10.85 
xX 2.054 7.85 1523 14.6 1.76 393.15 | 10.93 
1T, here entered, is the mean value of Ts and T,, previously given in tables 
4 and 5 and is not the general average thickness of the cortex of the sagittal, 
frontal arid horizontal sections formerly presented in my second paper in this 
series (Sugita, 717 a). 
Table 6 shows the values for the cortical volume computed by 
the above method and the ratios, the cortical volume at birth 
being taken as the unit of the comparison. 
Chart 2 (graph LWT) shows graphically the ratios obtained 
(table 6, column G), accompanied by the graph (graph LWH) 
which shows the increase in volume of the cerebrum (table 6, 
column B). The volume of the cerebrum was computed ac- 
cording to my previous procedure (Sugita, 17). From this 
