OPERATIONS ON THE FOOT 105 
tissue elements permeated by nerve fibres which have 
grown out from the axis-cylinders of the nerve stump. 
It may vary in size from a pea to a hazel-nut, and is 
frequently the cause of much pain. This must be cut down 
upon and cleanly removed, taking away at the same time 
as much of the nerve as is possible. 
Reunion of the Divided Nerve.—We may say at once that 
‘reunion’ in the popular sense of the word does not take 
place. At a varying period after section, however, we do 
get a return of sensation. This is brought about in the 
following manner: The axis-cylinder of the nerve, still in 
connection with the spinal cord, swells somewhat, and 
hypertrophies. The cells of this hypertrophied portion 
show a great tendency to proliferate and produce new nerve 
structure. This growing point splits, and gives rise to 
several fibrils, which are new axis-cylinders. These com- 
mence to grow towards the periphery, and, in so doing, 
grow through the cicatricial tissue that has formed at the 
seat of the operation. 
After passing through the cicatricial tissue (the amount 
of which tissue, of course, controls the length of time that 
insensibility remains), the growing axis-cylinders reach the 
degenerated portions of the nerve below the point of section. 
It is along the track of the old nerve that the new growths 
from the stump reproduce themselves. 
The fact of the new growths having to pass through the 
fibrous tissue of the cicatrix before they can gain the course 
of the old nerve, along which latter their progress of growth 
is comparatively easy, affords ample illustration that as 
large a portion as is possible of the nerve should be removed 
when operating, in order to convey insensibility for the 
longest time. After reunion, of course, nothing remains 
but to repeat the operation. 
The Existence of an Adventitious Nerve-supply.— While 
not exactly a sequel of the operation, the fact that it is not 
discovered until after the operation has been performed 
warrants us in mentioning it here. It is not an uncommon 
thing in the lower operation to find that sensation and 
