of the chest in breathing, speaking, and expression. 311 
Fig. 2. Plan of the respiratory nerves in their course 
through the body. 
A. The sterno-cleido-mastoideus muscle. 
B. B. The trapezius muscle. It is seen to arise from the 
back of the head, and from the spine ; it is inserted into 
C. The scapula, and 
D. The clavicle. 
E. E. The serratus magnus anticus. It is left at its attach- 
ment to the ribs, but cut off from its insertion into 
the scapula, so as to expose the trapezius and the 
spinal accessory nerve. 
F. The lower surface of the diaphragm. 
G. The upper surface of the diaphragm. 
H. The larynx. 
The four great muscles (A. B.B. E.E. F. G.) are asso- 
ciated together, and joined to the organs of the voice, and of 
smelling, &c. by the nerves displayed here. 
To simplify this view, the regular or symmetrical system 
of nerves is not presented in this drawing, but only the re- 
spiratory nerves. It is the entwining of nerves of distinct 
systems which produces the apparent intricacy. If the spinal 
nerves were represented crossing these, and the network of 
the sympathetic superadded to them, we should have all the 
seeming confusion of the dissected body. 
1. Respiratory nerve of the face, or portio dura of 
authors. 
2. The glosso-pharyngeal nerve. 
3. The superior respiratory nerve. It is seen to pass 
through the sterno-cleido-mastoideus muscle, and 
to supply it with branches : then to take a course 
