968 
sition of the total number of lymphocytes formed in the body into 
polynuclear cells the maintenance of the equilibrium is wholly 
explained. 
There was still to be explained why in the case of a repeated 
injection, inspite of a perfectly similar reaction of the blood, the 
polynuclear cells in the exudation occurred at a much quicker rate. 
The microscopic examination of the tissues in and around the 
abdominal cavity, treated in the above way gave a satisfactory 
explanation of all the phenomena. The rabbit used for this purpose 
was treated in the following way. 
Firstly an injection of 200 c.c. of NaCl 0.9°/, at a time was 
given on two consecutive days; on the second day a suspension 
with 0.25 cc. of leucocytes was drained off. After about 14 days 
the injection was repeated during three consecutive days and on 
the third day there were tapped of more than 1 milliard leucocytes. 
Six days later the injection was again repeated during 3 consecutive 
days and on the third day + 4 milliard leucocytes were obtained. 
About 4 hours after a renewed injection on the 4% day the rabbit 
was killed. ; 
The abdominal cavity contained more than 150 e¢.c. of fluid with 
an enormous quantity of leucocytes. All the abdominal organs showed 
a strong hyperaemia. Especially the omentum was rich in blood 
and swollen to a thick greyish-brown tissue. The omentum and two 
pieces of the mesentery with the portions of the small intestine fixed 
to them were hardened in sublimate and formol for further micros- 
copic examination. Slides of the omentum and mesentery coloured 
after Giemsa showed that a large proportion of the white blood 
corpuscles which had disappeared from the blood had been deposi- 
ted in the hyperaemic tissue. They were found in and around the 
blood vessels, sometimes in large conglomerates which consisted of 
lymphocytes of different seizes up to plasma cells. Between these 
groups there were fat cells and especially connective tissue which 
was of a pronounced formative type: Large fibroblasts, newly 
formed capillaries, plasma cells upto magrophags. 
In some places several cells exhibited nuclear division. Further- 
more the whole of the tissue was pervaded with a large number 
of leucocytes, in great numbers especially along the endothelial 
layer of the tissues. This was very distinct in a preparation of the 
surface-view of a thin part of the membrane; by far the greater 
number of the cells were polynuclear in this case. 
A number of the mononuclear cells clearly show a transition into 
the polynuclear form. Here and there occurred larger and smaller 
