84 The Opsonic Tndex — A Medico- Statistical Enquiry 
Number of 
Bacteria 
Ingested 
Means 
Standard 
Deviations 
Opsonic 
Index 
FiiEQUENCY Distribution of Leucocytes with 
Normal 
Serum 
0 
32 
1 
36 
2 
49 
3 
45 
i 
71 
5 
31 
6 
38 
7 
34 
8 
42 
9 
25 
10 
22 
11 
14 
1:2 
20 
13 
14 
13 
15 
5 
IG 
6 
17 
2 
18 
5 
19 
1 
20 
1 
21 
0 
22 
1 
23 
— 
24 
— 
25 
26 

28 
29 
30 
31 
32 
33 
3J, 
35 
36 
37 
38 
39 
ho 
41 
42 
Test 
Serum 
9-93: 
6-94 
1-67 
Normal 
Serum 
with |t turn 
every 1' 
3-47 ± -09 
3-00 
Test 
Serum 
with ^ turu 
every 1' 
4-21 
1-50 
than couplets or triplets. A count was made of 500 leucocytes in both ways for 
both normal and immune sera. The results were as follows : — 
