GROWTH OF THE CEREBRAL CORTEX kai 
In the first phase occurs the rapid enlargement of the cell 
body and the nucleus, the cell retaining still the fetal form, and 
not showing any significant differentiation in the internal struc- 
ture. The Nissl bodies first appear as the so-called ‘Kernkappe’ 
at the end of this phase. The tone of color of the sections stained 
with the carbol-thionine is rather violet. 
In the second phase, the size of the cell body and of the nucleus 
continues to increase, but very slowly, and both attain their 
maximum sizes at the end of this phase. The differentiation in 
cytoplasm goes slowly on and the chromatin in the nucleus be- 
gins also to differentiate. The tone of the stain is transitional 
from violet to blue. 
Throughout the third phase and afterwards, the size of the cell 
body and of the nucleus decreases slowly from the maximum 
values attached at the end of the second phase. But the differ- 
-entiations of the cytoplasm and the nucleus chromatin steadily 
continue as the age advances. The apical dendrites gain in 
diameter and the basal dendrites begin to take the stain. The 
nucleus sometimes shows the ‘Kernfalte. The tone of the 
stain is rather blue and the contour of the pyramids clear cut. 
The ganglion cells of the lamina ganglionaris enlarge very 
rapidly and attain nearly their full size at the age of ten days— 
somewhat earlier than do the pyramids. But the morphological 
changes which take place in the ganglion cell body and the nucleus 
are similar to those just described in the pyramids. In the 
lamina ganglionaris there can be recognized two distinct kinds 
of nerve cells, one the smaller-sized pyramids, which seem to be 
very like the pyramids in the lamina pyramidalis, and the other, 
the larger-sized neurons, which are usually called ganglion cells 
or giant cells and which characterize the layer. Some of the 
cells found in the lamina ganglionaris and which grow to be the 
ganglion cells are from the first somewhat large-sized. These 
develop more rapidly than the other small’ cells in this layer, 
which are intermingled with them. In earlier stages the gan- 
glion cells manifest no structural difference or characteristics 
marking them off from the smaller cells, but differ only in the 
size of the cell body and of the nucleus. They retain their fetal 
