Vol. 6, 1920 PHYSIOLOGY: S. J. MELTZER 533 
In studying at various times certain phases of this experiment, I was 
sometimes annoyed by failures which were caused by early deaths of the 
animals. A survey of these failures revealed the fact that they took place 
in animals in which both ganglia were removed. A survey of the several 
changes in the functions which stimulation of the sympathetic nerves or 
section of these nerves bring about, shows that these changes, interesting 
as they are, affect only peripheral conditions, and do not endanger life. 
But some of the post ganglionic fibres of the superior cervical ganglion 
enter the "brain" before they reach the periphery. May not some of 
these fibres also terminate in some vital point within the brain or the 
medulla? It is true, in our previous experimental studies, death of the 
animal was rather an exception. But these studies were essentially con- 
fined to the removal of a ganglion on one side only. From experiments 
upon the vagus nerves we know that cutting of one vagus does not affect 
the life of the otherwise normal animal, while, when both vagi are cut, 
with few exceptions, the animal dies within a day or two after the opera- 
tion. May we not meet with a similar result by the removal of both 
ganglia? I therefore started a series of experiments in which both superior 
cervical ganglia were removed. 
This series of experiments was made chiefly on rabbits. Although in 
these animals the superior cervical ganglion is small, it offers the advan- 
tage that it is not intimately connected with the vagus nerve, as it is the 
case in dogs and cats; the ganglion in rabbits may therefore be readily 
removed without causing injury to the neighboring vagus nerve. (It is 
not superfluous to state that the present series of experiments were car- 
ried out last winter, beginning November 3rd.) To this date more than 
eighty rabbits were used for the study of various phases of our problem. 
I shall state the results briefly. 
For the chief issue of our problem we used twenty-eight animals in which 
both superior cervical ganglia were simultaneously removed under ether 
anesthesia. Of these, twenty-five died as follows: Six died in less than 
twenty-four hours, that is, the animal which was operated before noon or 
in the afternoon was found dead next morning at about nine o'clock. 
Nine animals died in less than two days, five in less than three days, one 
in four, one in five, one in six, one in eight and one in ten days. The 
autopsies revealed the presence of pulmonary lesions in all these animals. 
Three animals survived the removal of the ganglia and were killed after 
many weeks or months and no pulmonary lesions were found. 
Both ganglia were also removed in two cats which died in less than two 
days and showed pulmonary lesions. 
At an early stage of the investigation we met with one failure in a cat; 
it survived for many days the removal of both ganglia. Suspecting that 
the operation might not have been successful, it occurred to me, that 
this might be tested by the action of adrenalin upon the pupil. In the 
