2 94 Mr. Bell on the nerves which associate the muscles 
and pharynx ; it sends branches to the larynx in com- 
pany with the branches of the par vagum ; it then crosses the 
great nerves of the neck, passes under the spinal nerves, goes 
to no other muscles in its course, but lavishes all its branches 
on the mastoid and trapezius muscles. To an anatomist it is 
as plainly set forth as if it were written in our mother tongue, 
this is the superior respiratory nerve of the trunk * 
Comparative view of these nerves. 
If we examine the par vagum , the portio dura of the face, 
the external thoracic, the diaphragmatic, and the spinal acces- 
sory nerves, by comparative anatomy, we shall conclude that 
they are all respiratory nerves, by their accommodating them- 
selves to the form and play of the organs of respiration. In 
fishes, the respiratory nerve'f goes out from the back part of 
the medulla oblongata. When it escapes from the skull it 
becomes remarkably enlarged, and then disperses its branches 
to the branchias and the stomach. But from the same nerve 
go off branches to the muscles moving the gills and oper- 
culum, whilst a division of the nerve is prolonged under the 
lateral line of the body to the tail. It is said, this division 
sends off' no branches, but this is not correct ; it gives bran- 
ches in regular succession to the muscles from the shoulder to 
the tail. Experiments have been made upon these nerves, 
but their detail would lead us too far. It is scarcely necessary 
to add, that there is neither phrenic nor spinal accessory, nor 
* Lobstein, in a dissertation on this nerve, finding the difficulty of accounting for 
the nervous fluid coming by a double passage to the muscle, concludes, veniet forsan 
tempus quo istce quae nunc latent, dies extrahat et longioris aevi diligentia. 
f The nerve which by its subdivision supplies the heart, lungs, and stomach, 
and the muscles of the gills. 
