696 
Journal of Agricultural Research 
Vol. XXI, No. 9 
Cultures of Bacillus megatherium No. 270 and 734 were obtained from 
the American Museum of Natural History of New York City. No. 734 
was the de Bary strain, but the identity of No. 270 was unknown. 
Two rabbits were liyperimmunized against organism 1510-B by intra¬ 
venous injections of 0.5 cc. of a washed saline suspension of the organism 
on the first day, 1 cc. on the fifth day, 2 cc. on the twelfth day, and 
2 cc. on the nineteenth day. Samples of blood serum were then taken 
and were tested against carbolized normal salt solution suspensions of the 
organisms (agglutinating fluids). A sample of normal rabbit serum was 
also tested against each organism as a control. After 24 hours’ incubation 
at 37 0 C, the tests were read, as shown in Table III. 
Tabus III .—Agglutination tests 
Animal. 
B. megatherium, 270. 
0.04 
0.02 
O.OI 
0.005 
0.002 
0.001 
Hyperimmune rabbit A . 
+ 
+ 
? 
+ 
+ 
? 
4- 
+ 
+ 
? 
1 
? 
Hyperimmune rabbit B . 
Normal rabbit C . 
~r 
Animal. 
B. megatherium, 
var. de Bary, 734. 
0.04 
0.02 
O.OI 
0.005 
0.002 
0.001 
Hyperimmune rabbit A . 
+ 
+ 
+ 
+ 
4 
_L 
? 
. -* 
Hyperimmune rabbit B . 
1 
4 _ 
r 
1 
Normal rabbit C . 
4 
t 
Animal. 
Organism 1510-B. 
0.04 
0.02 
O.OI 
0.005 
0.002 
0.001 
Hyperimmune rabbit A. ... 
4 - 
+ 
+ 
4 - 
+ 
+ 
1 
j 1 
T 
Hyperimmune rabbit B. ... 
+ 
T 
+ 
Normal rabbit C . 
-f- j 
- j 
Anaerobic cultures of the three organisms on 3 per cent glycerin agar 
were incubated 18 hours at 37 0 C. with no apparent growth. At 60 
hours incubation these cultures all show minute dewdrop colonies. The 
same cultures were then incubated aerobically for 24 hours at 37°, pro¬ 
ducing a luxuriant growth, typical of Bacillus megatherium. 
The apparent identity of the organism 1510-B as Bacillus megathe¬ 
rium now appeared to be clearly established by its morphological and 
cultural likeness to the known organism of that name. It remained to 
be seen, however, whether the phenomenon of the souring of beef could 
be reproduced by a known culture of B. megatherium derived from a 
