878 PACINIAN 
One of the nerves of the palm with the corpuscles 
— and of natural size. After Henle and 
To the naked eye they here present a beautiful 
semi-transparent pearly lustre, with a whitish 
opaline streak along the axis, resulting from the 
greater proximity and density of the series of 
internal capsules. In some animals of this 
species they have speared to me almost want- 
ing. It is remarkable that in no instance have 
they been detected in connection with nerves 
purely motor, nor, it is affirmed, on the fifth 
nerve or the glosso-pharyngeal. 
The stalk pt as has been said, of a 
production of the neurilemma enclosing a single 
nerve-tube. It sometimes happens that there 
are two nerve-tubes, but then there are two 
corpuscles on the single stem, either in close 
apposition, or actually enveloped by a few cap- 
sules common to both. The nerve-tube in the 
stalk is undulating, and being accompanied by 
white fibrous tissue is easily distinguished by 
its peculiar structure. The artery and vein 
supplying the corpuscle are also included in 
the stalk. 
_ The channel which the stalk occupies in its 
passage through the capsules, is conical and 
comes to a termination at the proximal end of 
the innermost capsule. ‘It is furnished with a 
membranous wall, with which the fibrous tissue 
of the stalk is united on the inside and the 
several capsules on the other, and by this means 
the intercapsular spaces are preserved closed, 
and their fluid retained. This wall usually 
presents irregularities of outline, and often a 
cellular ap ce, where the capsules, and 
especially the inner ones, join it. It is perfo- 
rated by the ae os We fo ea some 
of the intercapsular spaces (fig. 482). 
The ps ee are inelastic mem- 
branes, analogous probably to the white fibrous 
tissue, and trnisheld with clear transparent 
nuclei that project chiefly on the inner surface. 
This is true of all the capsules, but in the outer 
system or those thicker and stronger ones be- 
tween which fluid intervenes, there is evidence 
of a double wall; for in addition to the clear 
BODIES. 
double line which distinguishes all, these pre- 
sent also on their outside, when seen edgeways, 
a series of dots, which indicate a system of 
transverse or circular fibres, and in fact the 
corpuscle, when brought into focus, shows no 
other fibrillation than this transverse one. Al- 
most all appearance of a fibrous texture is re- 
moved by acetic acid, so that the yellow or 
elastic fibre does not 2 to form any portion 
of the capsular membranes. The outermost 
capsule, indeed, is invested with both the 
elastic and the inelastic fibres, but these are to 
be regarded as belonging rather to the areolar 
tissue in which the corpuscles are imbedded, 
than to these organs themselves. The ca 
are united together by the wall of the 
rd bsg They 3 also joined here and 
there by partial membranous septa passing 
directly Ps obliquely across the intercapsular 
Spaces, and which sega tote of the same na- 
ture as the capsules themselves. Pacini de- 
scribes further a union of the capsules at the 
distal end in the axis of the corpuscle, which is 
denied by Henle and Kolliker to exist. I 
have had, however, unequivocal evidence of its 
existence, especially between the inner on 
when they roe heen artificially distended. by f 
water, omens it often appears to cease to~ 
wards the surface. When the end of the cap- 
sules is bent on itself, the line of this intercap- 
uf union is less easy to trace. Pe ; 
e small artery supplyi corpuscle 
subdivides in the channel of the stalk into its 
three, four, or more capillaries, which pierce — 
the wall and enter the intercapsular spaces. 
After advancing in these for a variable distance 
they form loops, and return by a similar route © 
to the small corresponding vein. In the larger 
corpuscles I have seen a little bunch of vessels — 
formed near the further end by some of these 
capillaries. In most cases a single capillary 
accompanies the nerve-tube as far as the central - 
capsule, and then passes for some way upon its 
wall, sometimes in a spiral direction. If a 
perfectly fresh corpuscle from the mesentery of — 
a cat be examined before the blood has drained — 
off, the addition of a little water will oc 
sionally induce a rapid movement of the con- 
tents of these minute vessels under the eye o} 
the observer, by gaining entrance to th 
interior; and few objects are more beau 
than the miniature circulation thus artificiall 
brought about for a brief period. The capil- 
laries have their proper walls, furnished with 
nuclei. a 
The central cavity, in size, and partieula 
in aa is liable to much variety. It 
been already stated to be not unfrequently ber 
upon itself towards the further end ; sometimes 
it is bifurcated, or, more correctly, branched, 
the offset then passing in a recurrent course 
either from the commencement or the middle 
part of its length. In this case the brar ho 
surrounded by the same series of internal close 
capsules, and external ones separated by fluid, 
which encircle the principal cavity, only ace ts 
modated to the irregular conformation. How-— 
ever the central cavity is modified, it alway: 
retains its transparent character, and on its inner 
Ly 
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