538 
PHYSIOLOGY: S. J. MELTZER 
PROC. N. A. S. 
the contraction of the adductors. Such compHcated continuous mus- 
cular activities suggest the control of a centre. This central control is 
maintained in a state of tonus. The hypothesis assumes that the tonus 
of the central laryngeal control is maintained by impulses coming contin- 
uously from the superior cervical ganglia. Some time after the removal 
of these ganglia the respiratory laryngeal centre loses its tonus and its 
coordinating activity upon the laryngeal muscles during respiration. The 
loss of coordination gives rise to results similar in some way to those 
consequent upon cutting of the vagus nerves. The difference between the 
two conditions is, that in cutting the vagus nerves, the peripheral {motor) 
innervation of all the muscles are simultaneously abolished, while after 
removal of the ganglia only the central control is eliminated. In this case 
impulses may still reach the laryngeal muscles from the respiratory cen- 
tre, but they will now contract in an incoordinate and harmful manner. 
Future experiments may reveal that the behavior and appearance of the 
glottis after removal of the ganglia differ from its behavior and appearance 
after cutting of the vagi. 
This supposed reflex action of the ganglia upon the control of the ah- 
tagonistic contraction of the laryngeal muscles is somewhat parallel to 
the action of the same ganglia upon the peripheral organs, for instance, 
upon the iris. In this instance it controls the width of the pupil by 
causing either a contraction of the dilator muscle simultaneously with a 
relaxation of the sphincter pupilae, or, it causes a constriction of the 
sphincter with a simultaneous relaxation of the dilator. 
As to the nature of the origin of the impulses, I compared above the 
ganglia with the glands of internal secretion. I append here a very brief 
report of a few experiments, the making of which was stimulated by the 
mentioned comparison. In four rabbits both superior cervical ganglia 
were torn away from their upper connections, but were left connected 
with the sympathetic nerves. In addition, two ganglia from another 
rabbit were placed deep in the wound before closing it. All four animals 
survived many weeks and were killed later by chloroform; the lungs were 
found normal. A fifth rabbit was killed six days after the operation in 
an experiment in which by accident only one foreign ganglion was added. 
At the autopsy a small abscess was found in the right middle lobe. Prob- 
ably, the animal would have recovered. These few experiments do not 
permit any definite conclusion; but the findings are suggestive. If fur- 
ther experimentation should give similar results, the question would be 
obvious: whether other sympathetic ganglia also possess some sort of an 
internal secretion. 
^ Meltzer, S. J., and Auer, Clara Mehzer, "Studies on the Paradoxical Pupil-Dilata- 
tion Caused by Adrenalin. I. — The Effect of Subcutaneous Injections and Instilla- 
tions of Adrenalin upon the Pupils of Rabbits," Amer. J. Physiol., 11, 1904 (28-36); 
Meltzer, S. J., "Studies on the Paradoxical Pupil-Dilatation Caused by Adrenalin. 
