GROWTH OF THE CEREBRAL CORTEX 15 
TABLE 1 
Giving the average uncorrected diameters of the nerve cells and their nuclei in the 
lamina pyramidalis and the lamina ganglionaris measured at the fixed locality 
(locality VII) on the frontal sections of the albino rat brain. The data are given 
for each brain weight group only 
LAMINA PYRAMIDALIS LAMINA GANGLIONARIS 
BRAIN WEIGHT | NO. OF | BRAIN Cell body Nucleus Cell body Nucleus 
GROGE SSS BS) | Weert iirdiameter diameter diameter diameter 
Transv.| Longit.|/Transv.| Longit.)/Transv.| Longit. Transv.| Longit. 
grams | mn a Lu LL Ke wel Bp 
I 3 OPIGH Ie onl elOkd/ 6.6 7 OvLOP 1s ela Sa WlOlo 
II (B) 5) O- 251 M1OFS) | =1320 PA) MO ses aS 2 |) PR) | SRG 
WU 5 08353 POF Seon lO) 12.4) Gale le 2ORGn | Mlseon| el onO 
IV 6 OFAS2 Ee ion |e tea NS: 5) | lise eel lemon meld a 
V 9 OeS42 14 Aa S| 194, 134 19m |) 2274 1G Bok hg 4 
VI 3 OF059 (SOR liad el 2aO Mie. 29) | OmAe esr ieel Ornelas 
VII 2 ORO I Se2h Save isron 42) | 2ON2a 25r al Grlee al yn) 
VIII 6 OFSAN IGE SOFAS TALON 1458) | 2028) 2627 | eli7e4 Ses 
IX 3} OF964) 1659) 52082) 15o7 |) 1624) 21545) 2856) |) TOR 1Ok6 
xX 3 12040 MGAG | e20 sy PP 4AsS: os. | ZION 2G elie alms 
XI 4 Pe W628) |) 2065) 14a | W6E 1 | 215) |) 2864) 18s se e1or4 
XII 2 1253 Geer lecOn Me man Gn mld: Ole 1s eee pel Se O Mae Sia 
XIII 5 Te 3350l) 1680) 8208 (2) TANG a V5.2) 20°44) 26.8) lvesnl) Lse4 
XIV 3 AAO lea E20 4S aS ot 20et 27 Onell lsies 
XV 5 S54 S pon | 2OKOM MASS 21 Qn \e2ie4 elenOn ail snG 
XVI 4 12656) 21520 TOUGH esas: | 14a 217 |) 291 |) Wea Toe: 
XVII 4 O20 |S eig (ONO NA con elo, 2220) | 28 Onl l Saal One: 
XVIII 8 1839) AS | 194s SG 145 2273) | 28:5 | Sear 1920 
XTX 1 1.924) 15.6 | 19.9 | 14.0 | 14.3 | 22.7 | 29.3 | 18.8 | 19.4 
XxX 2 ZnO D4 ae 2a LORS Soma 2os2uil) ole Anno on izle 
1 The uncorrected measurements of the cell body and the nucleus of the 
ganglion cells in these groups (Groups XII—-XIV) show a slight decrease, while 
in the corrected measurements (see table 3) no diminution in cell size has oc- 
curred in this stage. This slight decrease in size on the slide is probably due to 
some chemical changes which takes place in cytoplasm during this phase of 
development. The same phenomenon is to be seen also in the ganglion cells 
measured on the horizontal section, given in table 2, in Groups XII-XVI. 
longitudinal diameters and in the same proportion as the 
width of the brain has shrunken. As in the other measure- 
ments (Sugita, 717 a, ’18 a, 718 b), the correction-coefficient was 
W. D in fresh brai : 
based on irae. ad. for the frontal section and on 
THE JOURNAL OF COMPARATIVE NEUROLOGY, VOL. 29, NO. 2 
