28 MATHILDE M. LANGE 
clots together to granules which either form a network or larger 
‘lumps of granules (fig. 36). Strébe found that the white sub- 
stance of the spinal cord of vertebrates also swells up as a result 
of degeneration. This fact would to a certain degree strengthen 
Colosanti’s assertion that a kind of analogy existed between 
the myelin cord and the white matter. The degeneration reaches 
deeper into the myelin cords than into the ganglia layer and the 
neuropil. 
About ten hours after operation a further disintegration is 
noticeable in the myelin cords and the neuropil, whereas the , 
ganglion cells show hardly any further change. There isa marked 
increase in the number of nuclei in the neuropil as well as in 
the myelin cords. In the myelin cords this increase is due to 
the migration of blood-corpuscles. The fibers of the myelin 
cords are torn asunder, the myelin cords thus occupying more 
space at the distal end than is normally the case (fig. 23). Prob- 
ably the blood-corpuscles also migrate into the central mass 
of nerve fibers, but I could not ascertain their presence there 
with absolute surety. The increase in the number of nuclei 
in the neuropil is due to the amitotic or direct division of the 
glia nuclei, which have entered the central nerve-fiber mass 
along with the processes of the nerve cells (fig. 37). About 
one or two days after operation a large number of cells, all 
provided with vesicular nuclei, appear in the neuropil and 
then migrate to the most distal part of the stump. Together 
with the sarcoblasts they form the so-called second blastema 
(fig. 31). These cells are doubtlessly neuroblasts, for later on 
the ganglia are evolved from them. It is very difficult to find 
the origin of these neuroblasts. I am of the opinion that the 
glia nuclei contribute largely to their formation, for the glia 
nuclei are the only nuclei (besides a few nuclei of the connective 
tissue), which are normally embedded in the central mass of 
nerve fibers. But I must also draw attention to the fact that 
the nuclei of the neuroblasts are a little larger than the glia 
nuclei. ‘The neuroblasts are very similar in structure to those 
ganglion cells lying nearest the neuropil, which have been de- 
scribed as nude nerve nuclei. Perhaps these cells having been 
