GROWTH OF THE CEREBRAL CORTEX 129 
IV. GROWTH IN THE DIAMETERS OF THE CELL BODY AND OF THE 
NUCLEUS 
Chart 1 shows graphically the data given in table 3. As ordi- 
nates the average diameters of the cell body and of the nucleus 
of the pyramids (lamina pyramidalis) and of the ganglion cells 
(lamina ganglionaris) are plotted on the abscissa for the average 
brain weights. 
Diameter in micra 
56 ean) ae 7 = T T T Sree 1 T —— SS 
34 a | =| | | _— cal | i | — | 
| | | | See 
| | BE | pee eee GC 
SZ eal nae | Ls ell | Y ee 1 xx = SS Atal aa lela 
| | + | 
30 | ia T —— Sanit 1 I T7 a aa ee aaa & a i _— To at cal + ——s 
| | | | | 
| a4) | | lees 
28 a “i | t = = = = = 
A (ot 
26 pe —_ == se = | } i ee 
a | | 
| : | eo ee 
24 sae ee ee Se Ee a oe sew t —— GN 
r | | | eo a | | SSR | | | 
: | | Vga en | ee 0 ec ee ee ee 
22 A We ei Ea Ne Pe |e | | ae ies 3 a | 
Tals | | | | 3 
j Sole pai as ee | Pe 
20 linemen Zax oe ye == areal ar SI ad ead ae | 
is I a | | Uae | | pages oat ios ea 
a | ee ] | | 
| WA | | | | PN 
16 = {—— 
7 Wa | | | T 
Peed PEs 
44 yes VA | 18 | | nal ji i >. | 
| ] 
6 He | | | 
/ | | 
12 7 = hia | 7 + ai t 
A A | 
° / | | 
10 =I yr = 7 = = = = 1 = 
y | | 
8|_+ = = =r iba = 
| | 
6 a Ie a! £ 
4 =p | =| 
| T + t + — — 
Ba sa ' ! - 
| | | 
ol Je LL 
O1 02B03 04 05 06 
07 08 09 10 
———— 
THI lioie 1 1 i Gi dif Seed OMe AO) gins 
Chart 1 Showing the corrected average diameters of the cell body and the 
nucleus of the cortical nerve cells of the albino rat, plotted according to in- 
creasing brain weight. Based on the data in table 3. Graph GC, average diame- 
ter of the cell body of the ganglion cells in the lamina ganglionaris. Graph GN, 
average diameter of the nuclei of the ganglion cells in the lamina ganglionaris. 
Graph PC, average diameter of the cell body of the pyramids in the lamina pyra- 
midalis. Graph PN, average diameter of the nuclei of the pyramids in the 
lamina pyramidalis. X,10daysof age. XX and *, 20 days of age. **, 30 days 
of age. 
