Injuries of nerves and their consequences - Reflex Sympathetic ...

20 INJURIES OF NERVES.
are generally rounded off at the upper and lower ends,
and do not exhibit the lono-itudinal striation as do the
Pacinian bodies, but, on the contrary, transverse nuclei."*
Two nerves can be usually traced to these bodies, but their
after-relation to them is less clear. In some cases the
nerve seems to envelop the corpuscle spirally, in others,
to be lost in the centre of the mass. I have very little
doubt that in some instances of local nervous disease the
starting-point lies in the dermal nerve papillae. In a case
to which I shall have to refer, the corpuscles of Pacini
were certainly both too large and too numerous, and in
one which I myself have seen, there was some probability
that a neuroma of the thumb was merely an overgrown
tact corpuscle.
The corpuscles of Pacini consist of many concentrically
arranged layers of connective tissue, always becoming
more closely packed towards the centre, and surrounding
a cavity filled with soft, abundantly nucleated and easily
alterable material, which coagulates after death, and into
the interior of which the nerve fibres penetrate. These,
after they have lost the medullary sheath and the sheath
of Schwann,— which latter becomes continuous with the
laminated — sheath of connective tissue investing the corpuscle,
consist only of the axis cylinder, which terminates
in a little bulb.
The nerve corpuscles of Krause, described and depicted
by him as existing in the conjunctiva, genitals, and other
mucous surfaces, difl:er from the Pacinian corpuscles only
hy the absence of a thick, laminated investment.!
Most authors have held that these little bodies are apparatuses
of reinforcement (Vulpian) for the impressions
* Virchow, Cellular Pathology, translated by Dr. Chance, p. 277.
New York, 1861.
t Schultze, in Strieker's Histology, NewSyd. Soc. Transactions, p. 168,