90 NAOKI SUGITA ° 
TABLE 7 
Giving the computed number of nerve cells in the entire cerebral cortex, obtained on 
the basis of the measurements given in this series of studies. The ratio of the 
number of cells of each later group to that of Group IT (birth) is also given 
A | B | Cc D E 
COMPUTED 
oes weer ana | compurep | ‘Gromusin | CELLS | 3 
ER CORTEX ee PLR. AND 7. ee OF NUMBER 
WEIGHT L. Tesi _D Pe een W.DXT OF CELLS 
voLuMEs, K x ay 
100 
grams mms 
II (birth) 0.251 35.97 739 265.8 1.00 
Ill 0.358 61.81 590 364.7 1.8) 
IV 0.482 81.84 499 408 .4 1.54 
Vi 0.542 111.46 394 439 .2 1.65 
VI 0.639 144.50 305 440.8 1.66 
Vil 0.750 184.04 257 473.0 1.78 
VIil 0.841 210.54 240 505.3 1.90 
IX (10 days) 0.964 240.02 213 Sul? 1.92 
x 1.040 255 .94 198 506.8 1.91 
XI (20 days) eal 288 .93 186 537.4 2.02 
XII 1.2538 304.51 IZAl S201 1.96 
XIII 350 314.038 176 902.7 2.08 
XIV 1.445 329.71 165 544.0 2.05 
XV 1.554 345.86 149 515.3 1.94 
XVI 1.656 309.30 144 517.4 1.95 
XVII 1.726 365.08 146 533.0 2.01 
XVIII 1.839 397 .96 138 549.2 2.07 
XTX 1.924 390.39 132 Sls) 253 1.94 
xX 2.054 393 .15 131 playa) 1.94 
Average ey (Groups Nens) eae dns Aa eee 530.0 2.00 
Averages (Groups engl NON) 1a ne aes 530.2 2.00 
1 As explained in a footnote (footnote 4), the actual number of cells contained 
in the computed volume of the cortex should be N X L. F X W. D X T X 500, 
but, for the convenience, 1/100 of N X L. F X W.D X T, or 1/50,000 of the 
actual number of cells contained in the computed volume, was given here as 
the computed number of cells in the cortex. 
The above statement that between birthand maturity the 
number of nerve cells in the entire cortex has increased two- 
fold, does not necessarily mean that the additional cells have 
been all newly formed after birth. As a matter of fact, we see, 
