OF THE VETERINARY MEDICAL SOCIETY. 221 
Speaking of the division of the par vagum, he stated, that besides 
causing spasmodic contraction of the larynx through the recurrent 
branches, which we are all aware will, if the operation of tracheoto- 
my be not performed, cause almost instantaneous death by suffoca- 
tion, it produces direct effects upon the lungs, muscular fibres of the 
bronchi, and lining membrane of the bronchial tubes and air-cells. 
The lungs are thus deprived of their sensibility to ordinary impres- 
sions, and, even as Brachet has proved, of the necessity of breath- 
ing. An animal in which these nerves are divided may be drowned 
without any manifestations of distress, although it is seen to use its 
respiratory apparatus ; the muscles of which, although supplied 
with voluntary motor nerves, derive also a supply from the 
laryngeal branch of the divided nerve; for this branch arises 
from that portion which has still a communication with the 
brain, also from the external thoracic and phrenic, which are all 
nerves of organic life, inasmuch as the muscles to which they 
go continue to act during the animal’s lifetime. The muscular 
structure of the bronchi becoming palsied, al low's of an accumu- 
lation of mucus, which, if the animal be not previously destroyed, 
will cause death by suffocation. This, in his opinion, proves 
that they are not concerned in the secretions given off from any 
of the membranes situated in the cavity of the thorax. Diseases 
of the nerves, he observed, may be seen in tetanus, in which there 
is an inordinate supply of nervous energy, and in which the vo- 
luntary nerves alone are acted upon; in hydrophobia, in which 
the respiratory system is affected, and on which account so much 
difficulty is experienced in the act of deglutition ; and in string- 
halt, in which there is an irregularity in the action of the muscles 
arising from derangement in the function of the nerves. The 
morbid appearances found to exist in the gracilis and triceps 
femoris muscles of horses thus affected, he viewed as an effect 
rather than a cause of the disease. 
W. J. T. Morton, Secretary. 
