GROWTH OF THE CEREBRAL CORTEX 157 
Diameter in micra 
40, 
7 af 
| | 
38|——+ i SSS 
| | | za ire | ~oSs 
36 + — + poste 
| | Go “a 
ee a 4 
pe | 
32 Cae t : 7 
30; a+ — 
i} ale 
28 = 
| | ta eee ie 
26 i= oe Se 3 ise + 
= = ple = hs — = FO. — 
24 = S=s So ES = Sa GN 
Sse 
22) ih == 
H | 
20 | Sp tee + + 
| | o—__—_@ ———— 
-—_}—*. 
* | | a [al aS 
| | | DN! 
P| | PN 
40} T in | 
| | | 
44 — ib + = { 
| | | | 
| 
42. | 
| 
| | | | 
40 | ; Il Walt f= 4 =f 
8h | = T =? = 
6 a | 
| | 
4 + — } + == i 4 j Je Fe t 1 
2 | =} + ‘= - + utes 4 | 
ea 
A egeh  ( a Ml | 
40 if i 13 4 15 ie iT 18 19 20 2 22 23 2¢ pms 
Chart 2 Showing the corrected average diameters of the cell body and the 
nucleus of the cortical nerve cells of the Norway rat, plotted according to in- 
creasing brain weight. Based on the data in table 7. Graph GC’, average 
diameter of the cell body of the ganglion cells in the lamina ganglionaris. Graph 
GN’, average diameter of the nucleus of the ganglion cells in the lamina ganglion- 
aris. Graph PC’, average diameter of the cell body of the pyramids in the 
lamina pyramidalis. Graph PN’, average diameter of the nucleus of the pyra- 
mids in the lamina pyramidalis. 
THE JOURNAL OF COMPARATIVE NEUROLOGY, VOL. 29, NO. 2 
