MR. T. SNOW BECK ON THE NERVES OF THE UTERUS. 
217 
but being so fine it was impossible to trace them further, or to preserve them in the 
dissection. They measure -gwoth of an inch in diameter. 
The Ganglia at the Root of the Inferior Mesenteric Artery. — These ganglia, after 
receiving the terminal branches from the superior aortic plexus and branches from 
the three lumbar ganglia, furnish the nerves accompanying the inferior mesenteric 
and superior hsemorrhoidal arteries, and send from their lower border branches which 
form the inferior aortic plexus. The branches supplied by the lumbar ganglia are 
branches of the spinal nerves, derived in the same manner as those constituting the 
greater splanchnic nerve. These branches pass over the lumbar ganglia, and becoming 
associated with gelatinous fibres, end in the ganglia at the root of the inferior me- 
senteric artery ; in the same way as the branches passing over the thoracic ganglia, 
form the splanchnic nerve, and end in the semilunar ganglion. 
The Inferior Aortic Plexus. — The plexus, which forms a continuous plexiform 
arrangement extending from the root of the inferior mesenteric artery to its division 
into the lateral hypogastric plexus, below the bifurcation of the aorta, has been 
variously named : it has been called by Valentin Plexus divisionis aortae superior et 
inferior ; and the portion below the bifurcation of the aorta has been called by 
Tiebemann Plexus hypo gastricus niagnus superior, vel uterinus communis. It is formed 
by twelve or fourteen branches, which proceed from the inferior borders of the ganglia 
at the root of the inferior mesenteric artery, and passing inwards, unite with similar 
branches from the opposite side, and form a plexus in front of the aorta. The plexus 
has no distinct ganglia in its course, nor has it any marked division, but at the bifur- 
cation of the aorta six or seven filaments are sent along the common iliac artery. 
Some of these accompany the internal iliac artery, and join the pelvic plexus at the 
side of the vagina, whilst one branch joins the third sacral nerve midway between 
the third sacral foramen and the sacral plexus. The remainder of the nerves which 
pass along the common iliac artery from the aortic plexus accompany the external 
iliac artery. 
The inferior aortic plexus, an inch and a half below the bifurcation of the aorta, 
divides into the two lateral hypogastric plexuses, where a few crossing fibres occur. 
These crossing fibres are surrounded in this exposed situation by a dense cellulo- 
fibrous covering, forming a mass which has been figured and described as a triangular 
ganglionof a dense and firm structure. Only a small ganglion however exists in this 
situation. 
Lateral Hypogastric Plexus.-— It is difficult to ascertain what portion of this plexus 
Professor Tiedemann understood by the plexus hypogastricus lateralis, vel uterinus 
superior, but probably it was the middle portion, where he has figured it joined by 
the branches from the sacral ganglia. The plexus extends from the division of the 
inferior aortic plexus, to the junction of the branches from the sacral nerves at the 
side of the vagina, and forms a lengthened plexus, situated on the side of the pelvis. 
Like the inferior aortic plexus it forms no large ganglia in its course ; but the nerves 
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