parently also by Wagner. The latter admits
that in general the ganglionic corpuscles are
smaller than those occurring in the spinal
ganglia, and that the smaller corpuscles have,
as Robin observes, an oval shape, while the
larger are more or less spherical : there are,
however, according to him, cases where broad
nerve-fibres are seen passing off from small
cells, and where the large cells are connected
with small or narrow fibres. Sometimes, in-
deed, the ganglionic corpuscle has a narrow
tube on one side, and a broad one on the op-
posite side (see fig. 290.); and sometimes the
broad, sometimes the narrow, runs peripheri-
cally. Stannius has, as mentioned by Kolliker,
observed in Petromyzon cells present, of the
fibres connected with which the one was six
times broader than the other. Although, how-
ever, there does not appear to be a distinct de-
marcation between the ganglionic corpuscles
belonging to the two sizes, there can be little
doubt that the cells occurring in the sympa-
thetic ganglia are generally smaller than those
occurring on the cerebro-spinal nerves, both
in the fish and also in the higher animals.
The larger cells in the spinal ganglia of the

* Annales des Sciences Xaturelles, torn, septieme,
1847, p. 282. ; also Canslatt's Jahresbericbt, 1847.
f See Causlatt's Jahresbericht, 1847.



SYMPATHETIC NERVE.



443



ray appear, as Robin states, to be (in general
at least) connected with broad fibres, while
the smaller cells are connected with narrow
fibres : this, however, does not appear to be
invariably the case. In the sympathetic gan-
glia there are sometimes seen" connected with
narrow fibres cells as large as some of those
in the spinal ganglia, which are connected
with broad fibres. Moreover, as already
stated, there appear to be transitional sizes
between the larger and smaller variety of cor-
puscles. Kolliker also calls attention to the
fact that small ganglionic corpuscles occur in
other parts than in the sympathetic, as for
example those in the brain and spinal cord. It
would seem, then, that just as the finer
variety of tubular nerve-fibres cannot be re-
garded as characteristic of the sympathetic
system, so also the smaller variety of gan-
glionic corpuscles cannot be regarded as pe-
culiar to it either.

It has been already stated, that the nerve-
fibres which compose the posterior root of
the spinal nerves in the ray, &c., have all,
according to Wagner, ganglionic corpuscles
developed upon them. He concludes from
this, that all sensory fibres are so constituted,
and that we have thus a good mark by which
a sensory nerve-fibre may be distinguished
from one possessed of motor properties.
To this view, however, it is objected by
Kolliker, that in the higher animals at least,
so far is it from being the case, that all the
fibres in the posterior roots of the spinal
nerves are provided with these structures,
that not one of the fibres proceeding from the
spinal cord enters the ganglion at all, the
nerve fibres connected with the ganglion be-
ing fibres which arise in it and run peripheri-
cally, not one of them passing in the opposite
direction towards the spinal cord. In ex-
amining the spinal ganglia of the mouse, after
addition, as Kolliker directs, of dilute solu-
tion of soda, I have often had no difficulty
in observing, that a great portion at least of
the fibres in the posterior root run past the
ganglion without forming any connection with
its corpuscles, and, moreover, that the fibres
of the ganglion appear to be directed periphe-
rically, as he states.*

* A paper on multipolar ganglion-cells has been
published by Remak in the Monatsbericht der
Konigl. Preuss. Akademie der Wissenschaften zu
Berlin flir Januar., 1854, translated also in the
Edinburgh Monthly Medical Journal for April,
1854. He mentions that it was first made known
by Stilling's discovery of the so-called nerve-nuclei
in the pons Yarolii of man and of the mammalia,
that the multipolar ganglion -cells discovered by
Purkinje, MUller, and himself (1837), in the cen-
tral organs of the vertebrata are connected with
motor nerve -fibres. It has also been ascertained by
Wagner (1847), that each of the large multipolar
ganglion-cells of the electric lobes in the torpedo
becomes continuous by means of a process with the
axis cylinder of a fibre of the electric roots of the
n. vagus and trigeminus. The other branched pro-
cesses of these cells, distinguished by their granular
or striated appearance, serve the purpose, according
to Wagner, of connecting the cells with each other.
Remak could not, however, in an examination of
the Torpedo marmorata find such connections. On



Connection bettueen the Sympathetic and
Cerebro-spinal Systems. By the older ana-
treating the fresh brain with a solution of sublimate
or of double chromate of potash, the electric lobes
are easily separated into their constituents. All
the ganglion-cells are multipolar, surrounded by
delicate nucleate sheaths, and occupy the meshes of
a network formed of wide vessels with thick walls.
The processes destined for the formation of the
electric roots of the vagus and trigeminus collect
themselves at the base of the cerebral lobes into
strong bundles visible to the naked eye. The re-
maining branched processes, becoming surrounded
by a thin medullary sheath, form nerve-tubes with
dark borders, which pass into the medulla oblongata.
A connection of the cells with sensory fibres has
not as yet been demonstrated ; the sensory roots of
the vagus and trigeminus do not pass into the
electric lobes ; rather those of the former pass into
the medulla oblongata, those of the latter into a
gray appendix of the cerebellum (feuillet restiforme
of Lerres and Lavi), which in its structure, par-
ticularly in the size and form of its multipolar
ganglion-cells, agrees with the cerebellum, but not
with the electric lobes.

He mentions that he has in his possession trans-
verse and longitudinal sections from the spinal
cords of man and of the ox, prepared by Stilling,
in which, as mentioned by the latter, the passage
of nerve-fibres belonging "to the motory roots into
multipolar ganglion -cells of the anterior gray co-
lumn is observed. He finds also in the transverse
sections small bands of broad nerve-fibres with
dark borders, which seem to unite the anterior and
posterior roots. From the place of entrance of the
anterior roots into the anterior gray columns, or
commencing at the onter circumference of the latter,
they run as far as the posterior surface of the sub-
stantia gelatinosa, where the posterior roots enter
the latter. Here they are connected with the gan-
glion-cells, which send one of their processes to the
sensory roots, while the chief mass of the latter
radiates in broad thick bands through the gela-
tinous substance into the posterior gray columns as
far as the seat of the large multipolar ganglion-
cells. These circular bands of fibres may be pre-
sumed to indicate one of the paths on which in
decapitated animals the stimuli applied to sensory
nerves gives rise to reflex movements. It is re-
markable in this respect, that the long axis of the
largest ganglion-cells has the same direction as the
long axis of the spinal cord, and that besides the
lateral processes by whose means they are con-
nected with the fibres of the roots of the nerves,
they send out branched processes at both poles
tow'ards the cephalic and caudal extremities of the
spinal cord.

In the spinal ganglia the multipolar cells dis-
covered by Remak in 1837 in the ganglia are not
found. They consist rather, as he observed, in
fresh plagiostomes, without exception of the bipolar
cells simultaneously described by Robin and Wag-
ner (1846). These constitute, as shown by Leydig
in Chimaera monstrosa, nucleated swellings of the
axis cylinder, and are surrounded by a sheath con-
sisting of an epithelial layer, and of a firm mem-
brane, which is continuous with the sheath of the
nerve-tube. Bipolar cells may also be obtained
from the spinal ganglia of man and of the mam-
malia. They frequently appear unipolar when the
two processes leave the cell close to one another.
More frequently, however, as Kolliker observes, are
cells seen with a single process ; this probably di-
vides after a short course into two fibres. He finds
at least in the spinal ganglia of the mammalia (ox),
not unfrequently, divisions of nerve-tubes with
dark borders, which he misses in the plagiostomes.

Of the ganglia, it is exclusively the sympathetic
which are made up of multipolar ganglion-cells.
The sheath of the latter consists, as in the spinal
ganglia, of a delicate layer of cells and of a strong



444



SYMPATHETIC NERVE.



tomists, the sympathetic was described as a nerves, reinforced by fibres sent to it from
continuation of the fifth and sixth cranial the different-cerebro spinal nerves along its



membrane. The number of processes varies between
three and twelve ; by speedily branching they may
be increased threefold and upwards. The number
is regulated by the number of nerves connected
with the ganglion ; and hence it is smaller in the
main cord than in the solar plexus. The processes
have in general the optical and chemical properties
of the axis cylinder of the nerve-fibres. In the
solar plexus there are found, however, ganglion
cells whose processes are distinguished from one
another in a similar manner to those of the ganglion
cells in the electric lobes of the torpedo. Besides the
multipolar ganglion cells, bipolar cells are also ob-
served in the plagiostomata and mammalia. They
differ from those of the spinal ganglia, however, in
this, that both processes branch, thus coming to
agree essentially with the multipolar cells. The
same holds of the unipolar cells which, in the ani-
mals mentioned, are sometimes found along with
multipolar, and which in the batrachia and osseous
fishes, as well as in the head of the mammalia,
almost alone constitute the sympathetic ganglia.
In transverse or longitudinal sections of the thoracic
or abdominal sympathetic ganglia in the mammal
or plagiostome, the simple (generally very broad)
processes of such a unipolar cell are seen after a short
course to divide into numerous fibres, which pass
off from one another in different directions. That
all the processes take a peripherical course cannot,
according to Remak, be demonstrated, and is, from
what follows, improbable.

He has ascertained, namely, that in the mam-
malia the multipolar ganglion-cells of the ganglia
in the main cord of the sympathetic in the abdomen
and thorax become continuous by means of their
processes with the axis cylinder of nerve-fibres with
dark borders, of such, too, as pass from the spinal
ganglia into the ganglia of the main cord. In man
and in the mammal, each ganglion in the main
cord is , connected, by at least two branches, with
spinal nerves. The under branch (ramus com-
municans sympathicus s. revehens) is, according to
his observations, gray, contains very fine (the fibres
of Bidder and Volkmann) nerve-fibres, and very
many ganglion-fibres: it joins a spinal nerve for
peripherical distribution after it has at its place of
entrance, sometimes close to the spinal ganglion,
formed another ganglion consisting of multipolar
cells. The upper branch (ramus communicans
spinalis, s. advehens) is white : it contains the fibres
which, according to Wiitzer, &c., may be followed
to both roots of the spinal nerves. Remak has as
yet succeeded in seeing fibres of this branch enter
merely into the anterior root ; the remainder, gene-
rally the smaller number, are lost in the spinal
ganglion. The sensory fibres destined for the sym-
pathetic nerve must, therefore, as it appears, be-
come connected with cells of the spinal ganglia
before they pass into the main cord of the sympa-
thetic. The fibres of this spinal communicating
branch either pass directly into the ganglia of the
main cord, or they form in part separate white
bundles, which apply themselves to the cord, and
are lost in the next ganglion behind. Since, now,
as transverse sections of the glangia in the main
cord show, all entering spinal fibres become con-
nected one after another with multipolar glanglion-
cells, it follows that if the anterior roots of the
spinal nerves contain merely motor fibres, the
posterior merely sensory, the multipolar cells in
the ganglia of the main cord are found as well in
the course of sensory as of motory nerve-fibres.
From these cells there pass off in the peripherical
direction both broad nerve-fibres with dark borders,
and fine fibres (fibres of Bidder and Volkmann),
likewise others in which no dark borders can be
observed. All these peripherical fibres may be
named sympathetic, in opposition to the spinal
fibres with which they are connected by means of



the multipolar ganglion-cells. There are no grounds
for the assumption that (human) sympathetic fibres
exist which do not stand in connection with spinal
fibres, and consequently not in connection with the
great central organs of the nervous system. So
also in the nerves passing off from the sympathetic
ganglia to organs no spinal fibres have as yet been
demonstrated in whose course no sympathetic gan-
glion-cells are found.

By the above results, it is merely established
that in the sympathetic ganglia the angles of
branching, or points where sensory and motor fibres
divide, contain ganglion-cells. The ganglia are not,
however, thereby established to have the function
of central organs, so far as we make them depend-
ant on the conflux of sensory and motor fibres, and
so long as there is no ground for supposing that
among the peripherical fibres passing from a sen-
sory or motor sympathetic ganglion-cell, as well
sensory as motor fibres are found. Ganglion-cells
have been observed by Leydig in the angles of
branching of sensory fibres in CarinariaMediterranea.
In the angles of branching of motor fibres gan-
glion-cells are only known in the great central
organs. This of itself gives ground for the ques-
tion, whether the sympathetic ganglia have the
function of central organs ; that is, whether in
them there are distinct sensory and distinct motor
cells, or whether each multipolar cell serves as a
medium of connection between sensory and motor
fibres. On the spinal communicating branches,
the question has not hitherto been determined,
because they are too long, and a trustworthy
microscopic distinction between the two kinds of
fibres is wanting. On the other hand, other obser-
vations favour the view that the multipolar cells
are connected both with motor and sensory fibres.
In ganglion-cells whose long axis is the same as
the long axis of the ganglion, there are frequently
seen two fibres entering at one pole and two pass-
ing off from the other. If all four fibres were of
the same kind, the cell would then form an anas-
tomosis between fibres of the same kind, as has only
once hitherto been observed by Leydig, as a variety
of the bipolar cells in the Casserian ganglion of
Chimera monstrosa. If, moreover, in a small
multipolar ganglion taken from the solar plexus of
a mammal (ox), the number and direction of the
nerves passing to and from it be compared with the
number and the direction of the processes of the
cells, as seen on a transverse or longitudinal section
of the ganglion, the fullest correspondence is found
to exist between them ; that is, in such a multipolar
ganglion each ganglion-cell is connected with
nerve-fibres of all the nerves which are connected
with the ganglion. That in these cases, each of
the nerves entering or leaving the ganglion con-
tains only sensory or only motor fibres is, however,
improbable for this reason, that in other multipolar
sympathetic ganglia, for example, the ciliary,
otic, and spheno-palatine, we know that the enter-
ing nerves contain sensory as well as motor fibres.

If the sympathetic ganglion -cells serve as con-
necting media between sensory and motor fibres,
then the impressions made upon sympathetic sen-
sory fibres may be transferred by these ganglion-
cells to sympathetic motory ; through the medium
of the spinal sensory communicating fibres they
will also be enabled to act upon the great central
organs (brain and spinal cord), and thence through
the spinal motory upon the sympathetic ganglion-
cells and their motor processes. Besides the sym-
pathetic sensory and sympathetic motory fibres, the
assumption of a third set of sympathetic fibres,
serving immediately for nutrition, is not required
by any fact in physiology, since it is possible to ex-
plain the dependence of nutrition upon the nerves
by the action of the latter upon the contractile
walls of the blood-vessels.



SYMPATHETIC NERVE.



4-io



course. The communicating branch between
the carotid plexus and the sixth nerve, and
the deep or carotid branch of the vidian,
were regarded as the roots by which the
nerve commenced, while the different branches
passing between it and the other cerebral and
spinal nerves, were believed also to be entirely
composed of fibres sent by the latter to the
sympathetic.

According to Bichat, the sympathetic is an
independent system of nerves ; the cords which
pass between it and the cerebral and spinal
nerves are not entirely composed of fibres
sent to the sympathetic, but are partly
branches transmitted by it to these nerves.

The observations of Petit and Fontana* had
already shown that the communication be-
tween the sixth nerve and the sympathetic
did not consist of fibres sent by the former
to the latter, inasmuch as the sixth nerve
was found to be thicker beyond the point of
junction with the filament than before.

In 1827 Retziusf showed that in the tri-
facial nerve in the horse there was present
a gray fasciculus of fibres distinct from the
white, and which seemed to take its origin in
the ganglion. Somewhat similar observations
were made by Varrentrap and Miiller on the
branches of the trigeminus, and by Giltay on
the glosso-pharyngeal, vagus, and superior
spinal nerves of the fish, &c. It was after-
wards noticed by Remak that the gray por-
tions of the communicating branches con-
sisted of fibres which were sent by the
sympathetic to the cerebro-spinal nerves to
be distributed peripherically with them. On
microscopic examination it was found by him
that the sympathetic contained a large num-
ber of fibres presenting a peculiar structure :
these he regarded as the proper organic or
sympathetic nerve -fibres, and believed that
while the sympathetic derived from the brain
and spinal cord all the tubular fibres con-
tained in it, the grayer portions of the rami
communicantes were composed of organic
or sympathetic fibres, which were sent by
the sympathetic to the cerebro-spinal nerves,
to be distributed peripherically with them.
The same view was also adopted by Miiller
and others. Valentin, as has been already
stated, rejecting the fibres of Remak as being
destitute of the properties of nerve-fibres,
believed that the rami communicantes con-
sisted entirely of fibres sent by the brain and
spinal cord to the sympathetic. Volkmann
and Bidder, though agreeing with Valentin
in regard to the fibres of Remak, still main-
tained the opinion, that the rami communi-
cantes are of a compound nature, containing
fibres which are sent to the sympathetic from
the cerebro-spinal nerves, and also others
which are sent to the latter by the sympa-
thetic, and which belong to the fine variety of
tubular fibres already described as probably
arising in part from the ganglionic corpuscles.

* Selbstandigheit des Sympathischen Xervensys-
tems von Bidder und Volkmann, p. 29.
t Ibid. t Ibid.



On examining the connection between the
sympathetic and cerebro-spinal nerves in the
frog, they find that all the anterior branches
of the spinal nerves communicate with the
sympathetic. The filament of communication
with the first spinal nerve at its entrance into
it divides into two portions, one of which
proceeds towards the spinal cord, the other
towards the periphery : when it consisted of
two portions, the one was directed towards
the centre, the other ran peripherically. Con-
nected with the second spinal nerve they
found several communicating filaments, the
smaller portion of the fibres of which ran
towards the centre, while the larger portion
was directed towards the periphery. The
fibres connected with the third nerve also
ran in both directions, the chief portion,
however, towards the centre. The fourth
communicating branch sent its fibres both
towards the centre, and also towards the
periphery, the portion running centrally,
however, being much more considerable than
that running towards the periphery. So
also in regard to the fifth ; the portion, how-
ever, directed towards the centre did not
exceed that passing peripherically so much as
in the former. Sometimes they found that
the central and peripherical portions were
about equal. The sixth communicating branch
sent about an equal portion of its fibres in
either direction. In regard to the seventh,
they found that by far the greater portion was
directed peripherically, while only a very
small bundle took the direction of the centre.
Between the eighth nerve and the sympa-
thetic there are frequently two communicating
filaments : their fibres are directed almost ex-
clusively towards the periphery, only a very
small portion being directed towards the
centre ; and sometimes even this is wanting.
Between the ninth nerve and sympathetic there
are commonly two, often also three, filaments
of communication with the sympathetic; and
in one case they found as many as six : the
course of the fibres here is similar to what
it is in the eighth ; perhaps, however, the
portion sent inwards towards the centre is
even smaller, and not unfrequently fails alto-
gether. The communication with the tenth
nerve they found was not constant : some-
times three communicating filaments were
observed; at others no communication ap-
peared to exist. When present, they always
ran almost exclusively in the direction of the
periphery. Thus, then, of the rami communi-
cantes in the frog there appear to be none
which consist of fibres entirely derived from
the spinal cord, while, on the other hand, some
of these consist almost exclusively of fibres
which run towards the periphery, and which
therefore must be regarded as exclusively
consisting of fibres which are sent by the
sympathetic to the spinal nerves. The five up-
per spinal nerves give to the sympathetic in
the frog more fibres than they receive from it,
while, on the contrary, the five lower receive
from the sympathetic more fibres than they
send to it. As regards the communicating



446



SYMPATHETIC NERVE.



branches between the sympathetic and cere-
bral nerves, they also regard it as probable
that the greater number of the fibres in the
communicating branches run peripherically.
In the fish and bird they also found that the
fibres of the communicating branches were di-
rected partly towards the centre and partly to-
wards the periphery. In small animals belong-
ing to the class mammalia, such as the rat and
mole, as well as in small dogs and cats, they
found, on examining the communicating
branches with the microscope as before, that
the fibres passed both inwards towards the
centre, and also outwards towards the peri-
phery, and that the latter in many cases ex-
ceeded the former.

As already mentioned, there are commonly
two branches of communication between
each of the spinal nerves and the sympa-
thetic in the higher animals. The one of
these presents a white appearance, resem-
bling more or less the ordinary nerves of
the cerebro-spinal system; the other has fre-
quently a more gray aspect, approaching in
this respect the appearance of the sympa-
thetic nerves. Sometimes the white cord
presents the appearance of being composed
of a white and a grayer portion running to-
gether. As regards the minute structure of
the rami communicantes, the whiter portion
consists entirely of tubular nerve-fibres, both
of the coarser and finer varieties ; there are
also not unfrequently present fibres which
appears to be intermediate in point of breadth.
In general the broader variety of fibres ap-
pear to be more numerous than those which
belong to the finer variety. According to
Kolliker, the relation between them is much
the same in point of number as in the pos-
terior roots of the spinal nerves. The gray
portion, as is stated by Todd and Bowman,