THE GREAT ORGANIC NERVE. 
469 
together and surrounding each other, now blending together, 
and now separating, then with strange confusion crossin g 
each other in every direction, so that we have scarcely passed 
the border of this congeries of nerves, when we cease to be able 
to follow either of the contributory branches, and have only the 
mingled substance of all. This ganglion, or collection of ganglia, 
has no determinate shape in any of the domesticated animals ; 
except that you may trace a somewhat convex border posteriorly, 
and one more concave anteriorly in the direction whence the 
contributing branches came, and thus forming a rude kind of 
crescent. From the convex border of this lunar, I would rather 
call it solar plexus, there are divergent filaments of different 
consistence and size, and some of them minute, filmy, “ sha¬ 
dowy.” These are rays, radiations of nervous influence yet 
strangely mingling and interweaving with each other, and com¬ 
bining the properties and the powers oi the different principles of 
organic life. Therefore we no longer speak of particular nerves, 
or branches of nerves, but of plexuses ; and we give them a 
name from the viscus or part to which they are directed. I will 
not detain you by describing all of them, but I would urge you 
to follow them in some slow and careful dissection, and observe 
how every viscus and every portion of the organic system which 
the abdomen contains lives and acts by influence derived from 
this central sun. 
The different Plexuses from the Semilunar Ganglion .—The 
names and the connexions of some of these plexuses I must 
briefly run over. The anterior mesenteric I find upon the root 
of the anterior mesenteric artery. As the ganglion was com¬ 
posed principally from the great organic, so it retains the cha¬ 
racter of that nerve in the mode of its distribution. Whatever 
may be the ultimate destination or function of some of the 
fibrils, we find the plexus on an artery, not merely running along 
it like a motor or a sensitive nerve, but forming a tunic around 
it, penetrating it at every assignable point, and becoming, as it 
were, a portion and a part of it. We find this plexus first on 
the root of the anterior mesenteric artery; and composed, too, 
not merely of fibres from the semilunar ganglion, but from the 
lumbar nerves. The plexus pursues the course of the artery— 
accompanies all its branches—radiates on every side—spreads 
over the mesentery—encircles the various glands—reaches the 
small intestines—penetrates with the bloodvessels through their 
parietes, and ramifies on their internal surface. Other branches 
of this plexus I can trace to the coecum and the coecal portion of 
the colon. 
The Posterior Mesenteric Plexuses. —I have never lost sight 
VOL. VII. — 3 P 
