PROCEEDINGS 
OF THE 
NATIONAL ACADEMY OF SCIENCES 
Volume 5 NOVEMBER 15. 1919 Number 11 
THE INFLUENCE OF DEGENERA TION OF ONE VAGUS NERVE 
UPON THE DEVELOPMENT OF PNEUMONIA 
By S. J. Meltzer and Martha Wollstein 
Rockefeller Institute for Medical Research, New York 
Read before the Academy, April 28, 1919 
Since Galen's time experiments have been made upon the vagus nerve 
and it has been generally known that section of both nerves leads to 
an early death of the animal. It was however in the seventeenth cen- 
tury that it first became known, through the observations of Valsalva 
and Morgagni, that the section of the vagi causes lesions in the lungs, 
lesions which were designated by Vieussens as inflammation. Since this 
period numerous studies have been made regarding the nature of the 
influence of cutting of the vagi which leads to inflammation of the lungs, 
to pneumonia. Many investigators were of the opinion that the section 
of the nerves leads directly to changes in the pulmonary tissue. The 
last representative of this group of investigators was Schiff who in the 
forties of the last century described the lesion as being due to a neuro- 
paralytic action. At the same period, however, Traube carried out 
many series of well conducted experiments by which he seemed to prove 
that the section of both vagi causes lesions in the lung by paralysis of the 
oesophagus, which prevents the transportation of food into the stomach, 
and by paralysis of the nerves of the larynx, a paralysis which facilitates 
the entrance of food, saHva, and other foreign bodies into the trachea 
and the lungs. In other words, the pneumonia following section of both 
vagi was not due to direct changes in the lung tissue but indirectly to the 
entrance of foreign bodies through the trachea into the lung; the inflam- 
mation foHowing section of both vagi was of the nature of 'aspiration 
493 
