QS NAOKI SUGITA 
for the Albino rat. The numbers of cells in the lamina -pyra- 
midalis and in the lamina ganglionaris respectively and the num- 
ber of ganglion cells only in the lamina ganglionaris in five 
adjoining squares, each 100 micra on each side, were counted 
and the numbers in the unit volume of 0.001 mm.’ computed 
(see part I) and recorded in table 10. The relative cell density 
mm 
Sa = SS SS SS SS 
| 7 |r 
| gal SE aa Gaia eT et} tt 
| ee 
60 |— ——;— +--+ : Bea + - ——-+— _ 
He aan Pe ola bela 
+ — +- —+> +4———— _ + + —t —— Se 
55 i t | =< iat 
| | 
| | 
ee al pal alae — 
ae | } | | | 
| ia == 
| | | | 
| | | | | | 
40} t—:——, “2 + ———— | 
| | 
5 = SSS SS ESSE = leeks) 
| | eres ee sauna 
| [Pcs eee cela a 
0 +— ———— p<" ———= — a a ns Cn ——— 
ma ees ee 2S SaaS 
| eal| SS ein | | 
25) Bee =a an GT alae oe 
| ile | | | 
20 —t a == es = — st 
| | | ] | 
| | | 
ee ie i a ees eee 
10 (ees el Ae ee eee [ave oe oo = 
| | | } 
| | | | | | | ¢ 
5\— - Ro bp pt 
leer | | | | 
eaesatl aed 
0! yeas =| af al | | | eee || ih ee aed [bee a) 
a TR GIS EE SUS IS SE SES PMS) a al IR 3 gms. 
Chart 3. Showing the areas of the cerebral cortex in the sagittal and the 
frontal sections and the areas of the whole frontal section according to the brain 
weight. Norway rat. This chart is comparable with chart 1, which gives the 
corresponding graphs for the albino rat. X—.—.— Xs Cortical area in the 
sagittal section. °¢ ef, Cortical area in the frontal section. *——eF, Area of 
the whole frontal section. All graphs were based on the data in tables 8 and 9. 
represented by the sum of the numbers of nerve cells in the lam- 
ina pyramidalis and the lamina ganglionaris is tabulated in table 
16, column D, and plotted in chart 4 as graph N’. 
VIII. DISCUSSION AND COMPARISON 
The foregoing data, treated in a manner similar to that adopted 
in the case of the Albino (part I), may now be used for discus- 
sion and comparison. 
