224 
MR. T. SNOW BECK ON THE NERVES OF THE UTERUS. 
costal nerves follow a similar course. Each of these visceral branches of the inter- 
costal nerves becomes associated with a portion of gelatinous fibres, as it passes over 
the thoracic ganglion of the sympathetic, on a level with the nerve from which the 
branch arises. Thus the splanchnic nerve, although essentially composed of tubular 
fibres derived from the cerebro-spinal nerves, has in its formation a portion of gela- 
tinous fibres derived from each of the thoracic ganglia. These two kinds of fibres, 
i. e. the tubular fibres and the gelatinous fibres, although associated together, are yet 
as distinct as the motor and sensitive tubules of the cerebro-spinal nerves, after they 
are mixed with each other ; for by spreading out the tubules of the splanchnic nerve, 
each set of fibres can be distinctly and separately traced to its origin and termina- 
tion. In the course of the gelatinous fibres down the splanchnic nerve, some ganglia 
are always to be found; sometimes one, when it is comparatively large; sometimes 
as many as three, when they are small and may be readily overlooked. Were it 
necessary to offer any confirmation to the fact, that the gelatinous fibres arise in the 
ganglia of the sympathetic, these ganglia on the splanchnic nerve would offer a ready 
and convenient demonstration; for by comparing the fibres which enter at their 
upper part with the fibres which pass out at their lower part, the latter are found 
considerably to exceed the former. The splanchnic nerve usually exists as a single 
round cord, having a ganglion at the lower part ; but occasionally we find it divided 
into two very distinct parts, one white and the other gray. In this instance the 
white part is chiefly composed of the tubular fibres, to which it owes its white aspect, 
yet it contains a small portion of gelatinous fibres ; and in like manner, the gray 
part, although consisting chiefly of gelatinous fibres, which give it the gray appear- 
ance, contains some tubular fibres. Although an interlacing of the tubular and 
gelatinous fibres occurs in the whole course of the splanchnic nerve, yet it takes 
place chiefly at the lower part below the ganglion. The apparent object of this in- 
terlacing is the due proportioning of the tubular and gelatinous fibres, which is 
found in the distinct funiculi, in which the splanchnic nerve terminates. The gela- 
tinous fibres of the splanchnic nerve enter the gray portion of the semilunar ganglion ; 
and although I have been unable to trace them further, yet I do not think they end 
there ; for in the sympathetic ganglia, which are so minute as to allow their struc- 
ture to be examined, without previous dissection of them, the nervous fibres which 
constitute the nerve upon which the ganglion is formed, all pass beyond the ganglion, 
after being joined by other gelatinous fibres, which come from the ganglionic cor- 
puscles of which the minute ganglion is composed. The tubular fibres of the 
splanchnic nerve enter the semilunar ganglion, and after spreading out in its differ- 
ent lobes, pass through it, and are found in the branches of the sympathetic which 
proceed from the ganglion. Although the semilunar ganglion, from its size and 
complex formation, is not well adapted for deciding a minute anatomical point, yet 
I have, by repeated and careful examination, assured myself that the tubular fibres 
which are found in the sympathetic branches proceeding from it, are all derived 
