GROWTH OF THE CEREBRAL CORTEX 145 
even invade the cytoplasm of the nerve cells, are usually regarded 
as neuroglia cells. 
.The method here used, of staining with the carbol-thionine the 
material fixed in Bouin’s fluid and imbedded in paraffine, reveals 
clearly only the size and shape of the nerve cells in the cerebral 
cortex. The more detailed structure of the cytoplasm and of the 
nucleus or the structure of the axis-cylinder and dendrites is not 
brought out by this method, and for the investigation of these 
characters other methods are required. 
VII. DISCUSSION 
According to the foregoing observation, the full size of the 
largest pyramids in the lamina pyramidalis (about 25 days in 
age)‘ is about 21x 27 uw for the cell body and 19x 21 y» for the 
nucleus, and the measurement of those largest at- birth® is 11 x 15 » 
for the cell body and 10 x 11 » for the nucleus, in the fresh con- 
dition of the material. The full size of the largest ganglion cells 
in the lamina ganglionaris (at localities VII and X, about 25 
days, for example)! is 27 x 37 uw for the cell body and 24x25 u 
for the nucleus, and the measurement of the largest ganglion cells 
at birth’ is 17x21 uw for the cell body and 14x16 wu for the 
nucleus, all in the fresh condition of the brain. . 
If the volume of the cell bodies or of the nuclei be comparable 
among themselves according to the cubes of their average diame- 
ters, the figures given in table 5 which presents the cubes of the 
average diameters of the cell bodies and of the nuclei of the nerve 
cells at different ages, and which were calculated from the data 
in table 3, may be used as the basis of discussions on the volume 
development of the cells. It will be seen from table 5, by a 
4 To obtain the values here given, the uncorrected diameters of the cell body 
and the nucleus in Groups XI-XIII in the frontal and the horizontal sections 
(tables 1 and 2) were respectively averaged and the results were corrected b 
multiplying by the mean correction-coefficient of Groups XI-XIII for the 
frontal and the horizontal sections (see table 3). 
> To obtain the values here given, the uncorrected diameters of the cell body 
and the nucleus in Group II in the frontal and the horizontal sections (tables 1 
and 2) were respectively averaged and the results were corrected by multiplying 
by the mean correction-coefficient of Group II for the frontal and the hori- 
zontal sections (see table 3). 5 
