973 
occur in 1 c.m.m. of the blood which flows from a vein 
in the ear of a rabbit, amounts to about 7000—12000. Of 
these about 75°/, are lymphocytes and about 25°/, gra- 
nulated cells. After an injection of NaCl 0.9°/, in the 
abdominal cavity there is a very considerable decrease 
in the number of cells in the blood in whichbothkinds 
of cells take part in the same degree. This diminution 
reaches its: minimum already after a few hours and 
then makes place for a gradual increase again. 
The cells which have disappeared from the blood 
are met with again in the abdominal cavity; the fluid 
here rich in cells contains, however, almost exclusi- 
vely polynuclear leucocytes. The lymphocytes take 
part in the formation of a young formative tissue 
which clearly bears the characteristics of myeloid 
tissue. Here in many places and accompanied by an 
increase in the number of cells lymphocytes are seen 
to pass over into myelocytes and polynuclear cells by 
the way of plasma cells, which polynuclear cells 
spread out from the centre where they originate. The 
result also of the created disturbance of equilibrium 
is in the first place direct emigration of polynuclear 
leucocytes and besides that the formation of myeloid 
tissue at the place where the disturbance of equili- 
brium was brought about. In the formation of this 
myeloid tissue the greater majority of the lympho- 
cytes which have disappeared from the blood take 
part; by way of this myeloid tissue as intermediate 
station finally also the lymphocytes partly at least 
land in the exudation as polynuclear cells. 
Groningen, Februari 1920. Physiological Laboratory. 
