466 
leucocyte-free milk is quite as active as the leucocyte-rich sediment 
obtained by centrifugation. 
Table- N o. lb— Milk' from a healthy cow (No. 2). 
[Was centrifuged for 20 minutes at 1,500 revolutions per minute. Part of the supernatant fluid was 
{ massed through a Berkefeld filter and a clear bluish serum obtained. Five sets of tubes were inocu- 
ated with twenty-four hour agar cultures, (1) the filtered clear serum, (2) the supernatant fluid free 
from leucocytes, (3) the sediment rich in leucocytes, (4) the original whole milk, and (5) sterilized 
milk. The inoculations were made 3 hours after milking.] 
Bacteria 
per loop, 
at once 
after inoc- 
ulation. 
Bacteria per loop after 
8 hours at 37° C. 
Shaken 
moderately 
before 
planting. 
Vigorous 
agitation 
before 
planting. 
B. typhosus in filtered milk serum 1 
B. typhosus in leucocyte-free, supernatant fluid 
B. typhosus in leucocyte-rich sediment 
B. typhosus in whole raw milk 
B. typhosus in sterilized milk (control) . . .- 
22,000 
19. 000 
32. 000 
3,500 
16. 000 
10,000 
1,900 
3,600 
1,200 
a b 160, 000 
15, 000 
B. lactis aerogenes in filtered milk serum 
B. lactis aerogenes in leucocyte-free supernatant fluid. 
B . lactis aerogenes in leucocyte-rich sediment 
B. lactis aerogenes in whole raw milk 
B. lactis aerogenes in sterilized milk (control) 
Original milk 
33. 000 
4,000 
42. 000 
5,400 
36.000 
a b 330, 000 
210 
740 
33 
a b 360, 000 
19 
42 
92 
i 
a- Innumerable. 
b About. 
This series also shows the effect of shaking the milk in breaking up 
bacterial clusters. 
Table No. 15 A. 
Immedi- 
ately 
after 
inocula- 
tion. 
3 hours 
at 37° C. 
6 hours 
at 37° C. 
9 hours 
at 37° C. 
B, Lactic aerogenes. 
Whole milk 
1,500 
30 
' 2 
46 
Sediment, rich in leucocytes 
1,200 
31 
5 
34 
Milk serum, no leucocytes 
1,400 
52 
8 I 
370 
Control, sterilized milk 
1,300 
25,000 
200,000 j 
(a) 
B. typhosus: 
Whole milk 
7,200 
5,000 
1,500 
1,700 
Sediment, rich in leucocytes 
6,100 
2,400 
2,300 
1,600 
Milk serum, no leucocytes 
4,200 
2,800 
3,900 
14, 000 
Control, sterilized milk 
3,700 
15,000 
67,000 
(a) 
a Innumerable. 
This milk was obtained from a healthy cow (No. 2) in a cleanly 
manner, but wdthout special precautions. The milk w^as brought to 
the laboratory and inoculated wdth the cultures twm hours after 
milking. The times given, however, are from the tune of inocula- 
tion. When obtained, the whole milk contained 1,200 bacteria per 
