writers have also described various cytological and histological features 
occasionally to be observed in microscopic preparations. BYKOWSKI, 
Nusspaum and Reıs (1, 9, 10, 11, 13, 14) have provided detailed 
accounts of what they state to be gas bubbles arising in the cytoplasm 
of the gas gland cells and I have confirmed these observations in 
several series of stained microscopic preparations. JAEGER (4) and 
ByKowskı & NuSBAUM have also described a process of haemolytic 
disintegration of the blood as sometimes occurring in the capillaries 
of the rete mirabile and gas gland — descriptions which I again have 
confirmed in at least two series of gland sections. Finally may be 
mentioned the large amount of granular matter to be found in the 
bladder lumen adjacent to the oxygen gland, especially in conjunction 
with gas bubbles. In view of these facts and others to be mentioned, 
all observed, it must be remembered, in stained microscopic pre- 
parations, various authors have individually contributed towards the 
founding of the following theory. In the supply of oxygen to the 
ordinary tissues of the body the gas is of course combined with the 
haemoglobin of the red blood corpuscles, and is only liberated from 
this combination into the blood plasma as the partial pressure of the 
oxygen already dissolved in the plasma is lowered by absorption of 
the oxygen by the tissues. Now the cells of the oxygen gland differ 
from the other tissues of the body in that, being already employed 
in pumping oxygen into the bladder, they are in no special need of 
it for metabolic purposes, and even if they were able to abstract the 
oxygen from the blood plasma in the same way that other tissues do, 
this method of abstraction would be quite inefficient in view of the 
fact that the oxygen required by the gas gland must be abstracted 
both in relatively large quantity and at a relatively rapid rate 
(WoopLAND). Starting with this assumption, it would seem that the 
only alternative is for the gas gland cells to seize upon the main 
source of the oxygen in the blood, viz. the oxyhaemoglobin contained 
in the erythrocytes, and hence the a priori necessity for haemolysis 
or liberation of the oxyhaemoglobin into the plasma so that the gas 
gland cells can readly absorb the oxyhaemoglobin in solution. In- 
cidentally it may be remarked that the statements concerning this 
haemolysis were made long before good a priori reasons for its 
existence had been broached. Granting that haemolysis does occur in 
connection with the activity of the gland, it seems to be necessary to 
assume that the gas gland secretes a lysin which effects this haemo- 
lysis (JAEGER). It is also possible that the striped appearance of the 
cytoplasm of the gas gland cells situated next the capillary is evidence 
15* 
