THE 
VETERINARIAN. 
YOL. Vll, No. 81.] SEPTEMBER 1834. [New Series, "No. 21. 
MR. YOUATT’S VETERINARY LECTURES, 
DELIVERED AT THE UNIVERSITY OF LONDON. 
LECTURE XLIII. 
The Seventh Pair of Nerves—their Double Origin and Function 
—The Sympathetic or Great Organic 'Serve—its Origin- 
Universal Connexion—presiding over the Functions of S utii- 
tion , Secretion , fyc. 
WE are now prepared for the consideration of the seventh 
pair of nerves, or, as it has been strangely called, the portio duia 
of the seventh, as if it were not essentially distinct fiom the 
auditory nerve in origin, structure, course, and function. 
Its Double Origin. —There needs only a moment’s inspection 
to convince you that this nerve arises from two distinct roots; 
one from the central column of the medulla oblongata or inferior 
surface of the spinal chord, and the other from the side of the 
compressed corpus olivare, or what we should have termed the 
corpus restiforme or lateral column in the human being. We 
can plainly trace the superficial course of the inferior portion 
across the medulla oblongata, and parallel with the pons varolii, 
and separated from it by a little sulcus ; and the nerve, or the 
inferior portion of the nerve, is the evident prolongation of this 
medullary chord. With a little trouble we can dissect away and 
turn over this inferior portion of the nerve, and then we have 
other fibres as plainly springing from the side of the medulla 
oblongata, running parallel with the first, comprised with them 
in one common sheath, and combining to form the seventh neive. 
Structure of the Nerve. —Minute anatomists have spoken, and 
with perfect truth, of the difference in the internal structure of 
different nerves. This is sufficiently plain in the larger neives. 
The continuation, as it were, of the pulpy matter of the biain 
in the nerves of pure sensation-^-the distinct filaments of the 
fifth pair—the single furrowed chord of the cerebro-visceral, 
are well known; so in this seventh pair, and chiefly in the 
inferior portion of it, the fibres of which it is composed can be 
traced without the aid of a lens, and also the minute filaments 
VOL. VII. 3 0 
