1901 - 2 .] Experimental Observations on Leucolysis. 293 
are swollen and disintegrated. We made a series of observations 
on the blood of pneumonic patients incubated with pneumococci. 
The first group examined consisted of non-fatal cases, with leuco- 
■cytosis of from 12,000 to 30,000, (a) before, and ( b ) after the 
■crisis. 
(a) Before the crisis we found rather less phagocytosis than 
normal blood showed, and a greater amount of leucolysis. 
(b) After the crisis the leucocytes behaved very much as those 
of normal blood. Broken down cells were more numerous. 
A second group of fatal cases with leucocytosis showed the same 
changes as the non-fatal before the crisis, while one fatal case with 
only 6000 white cells per c.mm. showed very little phagocytosis 
and very marked leucolysis as compared with normal blood. 
Bacillus anthracis. — Marked chemiotaxis and phagocytosis were 
exhibited. Many of the long filaments were found coiled in a 
series of zigzags into a circle inside a phagocyte or all that remained 
■of one. Again, a row of disintegrated polymorphonuclear cells 
might be found arranged along a filament. The large lymphocytes 
-again showed less phagocytosis than the polymorphonuclear cells. 
Practically, every white cell, with the exception of a few of the 
small lymphocytes, showed marked necrobiotic change. 
Bacillus mycoides. — The changes only differed slightly in degree 
from those found in the case of B. anthracis , and were rather less 
marked. Most of the cells showed necrobiotic changes — more than 
would have been expected from the action of a non-pathogenic 
organism. 
Bacillus diphtlierice. — The polymorphonuclear cells and large 
lymphocytes were all utterly disintegrated, and were only repre- 
sented by debris in the centre of little clumps of bacilli. Some of 
; the small lymphocytes contained bacilli, and only a few were 
iound unaffected. 
Spirillum cholerce. — The white cells reacted exactly as they did 
to B. diphtlierice. 
Bacilhis typhosus. — Evidence of chemiotaxis was not noticed. 
The polymorphonuclear cells and large lymphocytes showed only 
slight phagocytosis, and they exhibited only a moderate degree of 
necrobiotic change. The small lymphocytes showed very little 
-change. 
