534 
PHYSIOLOGY: S. J. MELTZER 
Proc. N. a. S. 
experiments with adrenalin,^ it was observed that when a gangHon was 
incompletely removed, instillation or subcutaneous injection of adrenalin 
did not cause the characteristic upon the pupil. I therefore applied this 
method to the surviving cat and found indeed that an instillation in a 
conjunctival sac as well as a subcutaneous injection of adrenalin neither 
caused a dilatation of the pupil nor a retraction of the nictitating mem- 
brane, the latter being one of the striking effects of adrenalin in ganglion- 
ectomized cats. The animal was then killed on the tenth day after the 
9peration, and it was established that neither of the ganglia were success- 
fully removed, and that the lungs showed no lesions. Also in one surviv- 
ing rabbit it was found that adrenalin caused no dilatation of the pupil 
of the right eye. The autopsy showed normal lungs, proved that the 
ganglion on the right side was only partly removed. Henceforth an 
adrenalin test was made on the pupils of practically all animals in which 
the ganglia were removed. This was also done in the above mentioned 
three rabbits in which the removal of the ganglia did not lead to the 
death of the animals. In one of these animals the effect of adrenalin was 
indeed insignificant; in the other two rabbits, however, the instillation 
of adrenalin brought a definite dilatation of both pupils. In some rabbits 
the removal was purposely restricted to one half, or a little more than 
one half, of one ganglion or of both. As a rule the part to be removed was 
first crushed and then torn away. In these cases the adrenalin test was 
made a day or two later; the result was negative, and the animal survived 
even when both ganglia were mutilated. 
However, in testing the success of the operation by the use of adrenalin, 
it has to be borne in mind that while a negative result prove that the cor- 
responding ganglion was incompletely removed, a positive adrenalin test 
does not necessarily prove that the ganglia were so completely removed as 
to bring about the death of the animal. It may be that the number of 
nerve cells the removal of which is sufficient to bring about a positive 
adrenalin reaction upon the pupil, is smaller than the number of cells 
which have to be removed in order to bring about the death of an animal. 
In other words, the presence and integrity of a small number of nerve 
cells may be sufficient to maintain life, while the balance of the cells serve 
only as factors of safety — a condition which is especially met with in glands 
with internal secretion. It follows that in the above mentioned surviving 
rabbits in which the adrenalin test was positive, we had no assurance that 
the ganglia were so completely removed as to bring about the death of 
these animals. (It has to be added that at the autopsy of the three ani- 
mals neither a minute macroscopical nor a microscopical search was made 
for possible remnants of the ganglia.) 
However this may be, this series of experiments showed that in about 
ninety per cent of the animals, the operative removal of both ganglia proved 
to be fatal to the animals — an experiment which, as far as I know, was never 
