1907.) Observations wpon Phagocytosis. 179 
It is worth while to notice that such a progression does not necessarily 
occur under the same conditions of experiment. 
Observation. 
Case.—Suppuration of thumb. 
1 vol. of blood, 
1 ,, citrated salt suspension of melanin. 
Four tubes were prepared, and incubated for different periods, with the 
following results :— 
POPMUIMEES ge ccoessecececeses 31 granules of melanin in 50 cells. 
UMMM  6occceapesudicnse: 28 3 ane 
11 010.5 Se eR 29 is 9 
PAN OURS J coho eee noes 31 9 
Here it may be inferred that the immune cells were of lowered activity. 
This we know to be so in some cases, where they do less work in their own 
immune serum than do normal cells. 
Observation. 
Normal Blood—In the case of normal blood, a slight progression in 
phagocytosis may be observed :— 
1 vol. of normal blood, 
1 ,, citrated salt suspension of melanin. 
Four tubes were prepared, and incubated for different periods, with the 
following results :— 
1B WAIN WEES! 2 ists dei ee ecetes 18 granules of melanin in 50 cells. 
30 99 @eesesseeseseeosece 16 99 99 
J], Voor 1 n,n ee ee 26 43 os 
FEN OUTS RS es case we acenagen 31 
Here, again, the progression might be due to a further formation of 
opsonin, or to the further time allowed for the process of ingestion. 
The progressive phagocytosis in normal blood is more forcibly shown in the 
following observation, where colon bacilli are used in place of melanin :— 
1 vol. of normal blood, 
1 ,, citrated salt suspension of colon bacilli. 
Incubated 20 minutes ............ 50 cells contained 151 bacilli. 
1 vol. of normal blood, 
1 ,, citrated salt suspension of colon bacilli. 
Incubated 30 minutes .........+.. 50 cells contained 399 bacilli. 
In considering whether the index obtained by using immune cells in immune 
serum, 7” vitro, correctly represents the phagocytic resistance of the patient’s 
VOL. LXXX.—B. P 
