528 * $$. WALTER RANSON 
more favorable pathway formed by the distal stump, and the 
large number of branches increases the probability that at least 
one branch will reach that pathway and develop into a fune- 
tional fiber. This multiplication of branches is, then, a means 
for compensating the loss of fibers in the scar. That more 
than one branch of a fiber of the central stump may make such 
connections and develop into a functional fiber is shown by 
the physiological experiments of Osborne and Kilvington (’08), 
who showed that when the peripheral stumps of the tibial and 
peroneal nerves were united with the central stump of the tibial 
nerve, and regeneration had taken place, it was possible by 
stimulating the peripheral end of the peroneal to obtain con- 
tractions in the muscles supplied by the tibial. These contrac- 
tions could still be obtained after the tibial nerve had been 
divided above the point of the previous union, thus showing 
that some motor fibers in the central stump of the tibial had 
sent at least one branch into each nerve. 
It seems probable, however, that at best only a few of the 
many branches of a central axon make connections with the 
distal stump and that the rest atrophy and disappear. 
2. Penetration of the scar and loss of fibers 
It is in the tracing of these new-formed fibers through the 
scar and into the distal stump that the study of the serial sec- 
tions, in their serial order, was found of most advantage, since 
in them it was possible to demonstrate very convincingly the 
origin and course of these fibers. 
As has been stated, the first nerve fibers make-their appear- 
ance in the exudate on the first day. These are the fine non- 
medullated branches of the medullated fibers (fig. 16). No 
nerve fibers at any time grow out into the exudate or scar from 
the distal stump. After the first day little progress in the out- 
growth of fibers is made for several days. A few fibers can be 
seen in the immediate neighborhood of the central stump on 
the second, third and fourth days, but in number and length 
they are not much in advance of those seen on the first day. 
This temporary arrest of the outgrowth of fibers is probably 
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