GROWTH OF THE CEREBRAL CORTEX Dat. 
of all groups), as compared with the standards. As already 
noted in chapter 9, the results obtained by the use of formulas 
are open to some error, and in addition the results in the underfed 
are subject to special correction of a few per cent for a fair com- 
parison, so that the differences recorded may be regarded as 
probably insignificant and the computed cell number in the entire 
cortex of the underfed may presumably be considered as equal 
to the standard number for brains of the sameage. If this is so, 
the process of the cell division in the cerebrum during early life 
must have been going on undisturbed even by the severe un- 
derfeeding, though both the size and the weight of the brain 
have been arrested in development by this, in some cases very 
considerably. 
12. SIZE OF NERVE CELLS 
The standard size of the pyramids (in the lamina pyramidalis) 
and the ganglion cells (in the lamina ganglionaris) in the cerebral 
cortex of the albino rats at different ages was presented in my 
sixth paper (Sugita, 718 ¢). In the present study on the influence 
of the severe underfeeding upon the growth of the cerebral cortex, 
the size of the nerve cells in the cortex was also determined by 
the measurement of the transverse and longitudinal diameters 
of the cell body and the nucleus in the pyramids (in the lamina 
pyramidalis) and in the ganglion cells (in the lamina ganglionaris) 
at locality VII in the frontal section, in the same manner as for 
the standard determinations (Sugita, ’18c¢). The results have 
been tabulated in table 12a (unpublished) and condensed in 
table 12 for each group. The average diameters of the cell body 
and of the nucleus are obtained by extracting the square roots 
of the respective products of the transverse by the longitudinal 
diameters, and these have been corrected, by applying the cor- 
rection-coefficient, to the fresh condition of the brain. The 
corrected average diameters have been tabulated in table 13 a 
(unpublished), compared respectively with the corresponding 
standard values for the brains of the same age, and condensed 
in table 13. The correction-coefficients which were used are 
given in table 12. 
