ON THE NERVES OF THE UTERUS, &C. 27 I 
second and fourth ; a remarkable plexus is thus formed, which 
contains several distinct ganglia. It distributes nerves to the 
body of the uterus, vagina, bladder, and rectum, the integuments 
of the upper part of the pubes, and the muscles of the inferior 
outlet of the pelvis. A few branches pass down to communicate 
with the fourth sacral nerve, where it gives origin to the pubic 
nerve. These nerves arise from the plexus in such a way as to 
resemble the ramifications of the venae vorticosae in the choroid 
membrane of the eye. 
The difference, therefore, between the nerves of the human 
uterus and those belonging to the uterus in the quadruped, con¬ 
sists in the formation of only one lateral hypogastric plexus, and 
consequently in the existence of only four nervous centres in the 
latter. There appear also to be more ganglia in the plexiform 
distribution of the sympathetic nerve. In the seal, several large 
ganglia are found in the broad ligaments of the uterus. 
The nerves belonging to the female organs of birds are distri¬ 
buted as follows: The sympathetic nerve is found close to the 
origin of the spinal nerves, protected by the double heads of the 
ribs, between which it runs. The spinal nerves, that correspond 
to the lumbar and sacral nerves in quadrupeds, emerge near each 
other; and as the sympathetic nerve communicates with each of 
them, and forms a ganglion immediately after their appearance 
from the vertebral foramina, there is an almost uninterrupted 
ganglion of considerable length, from which numerous filaments 
go off to supply the oviducts. Others run upwards, and are 
distributed on the ovaria. 
Near the termination of the oviduct, in the cloaca, a plexus is 
formed, nearly similar to the lateral hypogastric plexus in quadru¬ 
peds, which is distributed in a similar manner to the oviduct and 
cloaca. There is a similar pudendal nerve. 
Fewer ganglia are formed near the aorta than in quadrupeds ; 
. and scarcely any branches are sent from the common hypogastric 
plexus to the oviduct. 
In the frog, as there is no proper sympathetic nerve, the 
abdominal viscera are supplied directly from the spinal neiwes. 
These, soon after they emerge from the vertebral canal, become ^ 
slightly enlarged : this does not deserve to be called a ganglion. 
From each of the spinal nerves in the lower part of the back and 
loins, a small nerve is given off, which takes a direction towards 
the centre of the bodies of the vertebrae, where they unite with 
each other, and with the corresponding nerves of the opposite side. 
By this union, a flat nervous web is formed, which stretches 
across the aorta, and extends downwards into the pelvis: this is 
analogous to the splanchic plexus in hot blooded animals. 
