292 Proceedings of Royal Society of Edinburgh. [sess.. 
containing a large number of these cells from cases of asthma gave 
us some help in recognising the changes which they undergo. As- 
regards their behaviour to the organisms, some of the cells showed 
phagocytosis and took up from one to ten staphylococci, but many 
did not. Many show vacuolation of their protoplasm and then 
break down, and the last stage at which they can be differentiated 
is shown by an indefinite nucleus, surrounded by a few scattered 
granules. It now occurred to us that the presence of organisms 
in the cells might be accounted for by invasion on the part of the 
organisms, rather than by phagocytosis. In order to clear up this 
point we repeated the experiment with dead staphylococci, and 
were able to conclude that the attack was on the part of the 
leucocytes. We took several scrapings from a twenty-four-hour-old 
culture of staphylococci and mixed them with normal saline solu- 
tion in a test-tube, and boiled the emulsion for ten minutes. We 
then centrifuged the emulsion and added some of the deposit of 
dead organisms to a mixture of normal saline solution and blood, 
and incubated as before. We found that the polymorphonuclear 
cells had engulfed numerous dead organisms ; the large lymphocytes 
had also taken them up, but again in smaller numbers than the 
polymorphs. None were noticed in the small lymphocytes. Many 
of the eosinophiles contained nine or ten. Leucolysis was again 
found and the films were very interesting, as the great majority 
of cells showed only the earlier changes. Vacuolation, and oc- 
casionally some of the further changes, were found in polymorpho- 
nuclear cells, large lymphocytes, and eosinophiles ; the small 
lymphocytes seemed unaffected. 
In the case of other organisms, for purposes of comparison, 
we shall only refer to incubations made for half an hour and 
with cultures twenty-four hours old. 
Streptococci . — The changes found were identical with those 
shown in the case of staphylococci. 
Pneumococci. — Briefly, these excite less phagocytosis and cause 
slightly more leucolysis than staphylococci. Polymorphs, large 
lymphocytes, and eosinophiles take up from one to five cocci, and 
occasionally a small lymphocyte contains one or two. After being 
engulfed, the capsule of the organism seems to swell, so that a very 
clear picture is obtained in stained films. Many of the organisms 
