516 S. WALTER RANSON 
were two of these secondary branches, each ending in a little 
ring. More than one lateral branch may be given off from a 
single non-medullated fiber. On one fiber two such buds in 
the early stages of formation were separated by not more than 
twice their own diameter from each other. 
These early branches do not appear to develop much after 
the first day and on the second day are already overshadowed 
by the transformations of the axons of the medullated fibers. 
On the third day, coincident with the beginning of a cellulipetal 
degeneration in the fibers from which they arose, these branches 
and end bulbs become indistinct in outline and begin to lose 
their affinity for the stain. And after four days one can dis- 
tinguish only indistinet shadowy outlines of the bulbs and fibers 
(fig. 18, c). These products of the early regenerative activity 
of the non-medullated axons in the proximal stump are there- 
fore abortive and very rapidly undergo degneration. It is an 
interesting fact that their development in the proximal stump 
did not progress as far as that of the similar structures in the 
distal stump and underwent degeneration earlier. This early 
abortive regeneration is an expression of the local vitality of the 
cut fiber just as is that of the peripheral stump. The reason 
for the final degeneration of these products is to be found in 
the fact that a cellulipetal degeneration occurs in the fibers 
from which they arose, thus cutting them off from their con- 
nection with the cell body. : 
b. Cellulipetal degeneration. Coincident with the beginning 
of the degeneration of the products of the non-medullated fibers 
near the cut surface, changes are noticed in the fibers them- 
selves. These changes, first noticed on the third day, are well - 
advanced on the fourth and extend up the fibers as far as they 
are included in the section. On the eighth day the alterations 
in these fibers at various distances from the cut surface (meas- 
ured with the aid of a mechanical stage) are as follows: In the 
last 0.5 mm. there are only a few shadowy outlines of the non- 
medullated fibers; at 3 mm. from the cut surface the fibers can 
be clearly seen but are in the late stages of degeneration similar 
to those in the distal stump, on the same day and at the same 
