464 MR. youatt’s veterinary lectures. 
The double origin of the seventh nerve, from the central 
inferior, and lateral column of the medulla oblongata, enables me 
to account for all this with tolerable satisfaction. From the 
motor column I derive the power of voluntary action; from the 
lateral column, the involuntary action of some of the muscles in the 
performance of an organic function, and that varying to a con¬ 
siderable degree, according as circumstances may require ; and 
from the union of both, I have the power of exciting those mus¬ 
cles to more energetic and more widely combined action, for the 
discharge of this function when 1 please, or under circumstances 
of difficulty or disease. It is like the combination of the spinal 
accessory with the nerves of voluntary motion from the spinal 
chord, and which causes certain muscles of the neck and shoulder 
to be either subservient to the will, or unconsciously employed in 
respiration, or both, as circumstances may demand ; but the two 
roots, or sources of nervous influence, are here brought nearer 
together. 1 acknowledge, gentlemen, that this is a somewhat new 
view of the character and function of the seventh nerve. The double 
origin you cannot deny ; the function of the nerves, from the in¬ 
ferior central and from the lateral column, seems to be tolerably well 
established ; and it will be for you to inquire what better ex¬ 
planation you can give of the office of a nerve springing from 
both these columns. 
The Upper Cervical Ganglion .—At the base of the cranium, 
beneath, and in front of the atlas, we find a pyriform reddish 
body, of a somewhat soft consistence, and differing in bulk in 
various animals. It gradually contracts as it proceeds down the 
neck, and at length terminates in a cord or nerve. In the horse 
it is scarcely an inch in length before it has diminished to a mere 
cord—in the human being; it is said to extend from the skull to 
the transverse process of the third vertebra. Before it takes on 
the character of a cord or nerve, it either sends numerous fila¬ 
ments to neighbouring and even distant parts, or it receives 
them, or both, and particularly as it regards the cranial and spinal 
nerves. 
There is a communication with the sixth pair, but not of that 
important character that some have represented. A branch of 
the great organic was ramifying, or forming a nervous plexus 
over the carotid artery within the cavernous sinus; the sixth 
nerve passes over the artery at the same place :—the two nerves 
come in contact with each other—they exchange several fibres, 
and then both of them continue their course. Professor Mayo 
has given a very satisfactory representation of this in his out¬ 
lines of human physiology. There are two communications with 
the fifth pair, and of the same character, and accompanied by an 
