692 Journal of Agricultural Research vd. xxi, no . 9 
sporulation the organisms become symmetrically swollen, and the chains, 
naturally fragile, become even more so. The spores are equatorial. 
Figure 1 shows the microscopic appearance of organism 1510-B in the 
vegetative form (A) and in the immature (B) and mature (C) stages of 
sporulation. Isolated 24-hour colonies when slightly magnified are seen 
to be densely opaque at the center. The periphery is granular, with the 
the appearance of irregular circles composed of rhomboidal rugae. 
In Table I there is given a comparative digest of the cultural charac¬ 
teristics of Bacillus megatherium var. de Bary and B. megatherium var. 
Ravenellii, as given by Chester, 1 along with those of organism 1510-B, 
recovered from the specimen of sour beef. 
TabijO I. —Comparison of cultural characteristics of organisms 
B. megatherium var. de Bary. 
B. megatherium var. Ravenellii. 
Organism 1510 B of sour beef. 
Aerobe, flagellated, 2 
to 5 microns wide. 
Gram-positive. .. 
Gelatin liquefied 
Agar slant growth like 
13 . subtilis; yellowish. 
Potato, like 13 . subtilis; 
yellowish. 
Indol negative, hydro¬ 
gen sulphid (H 2 S) 
positive. 
Habitat, cabbage infu¬ 
sion. 
Aerobe and facultative anae¬ 
robe. Rod-rounded, 3 to 
3 times breadth. Chain- 
forming, spore - bearing. 
Rods not swollen. 
Slightly motile, ameboid... 
Gram-positive. 
Gelatin liquefied. 
Agar slant, white, glistening, 
elevated, sometimes yel¬ 
lowish, odor of sour milk. 
Potato, growth elevated, 
white, moist, glistening, 
spreading, rugose. Odor 
of stale milk. 
Litmus milk decolorized, 
slowly peptonized. Am¬ 
photeric. Alkaline. 
Indol negative. 
Habitat, soil 
Aerobic rod, rounded ends, 
chain-forming, spore-bear¬ 
ing. Rods symmetrically 
swollen at sporulation. 
Length 2 to 5 microns, 
width 2 microns. 
Slightly motile. 
Gram-positive. 
Gelatin liquefied. No gas 
fermentation in dextrose, 
lactose, and saccharose. 
Agar slant, smooth, dull, 
grayish white, luxuriant 
in 24 hours at 37 0 C. Sour 
odor. 
Potato, smooth, glistening, 
yellowish white, moist, but 
scant growth. 
Litmus milk coagulated, pep¬ 
tonized, decolorized. Neu¬ 
tral to P n . 
Indol negative. 
Plabitat, sour beef. 
Fermentation reactions as shown in Table II were obtained after 60 
hours’ incubation with Bacillus megatherium var. de Bary and organ¬ 
ism 1510-B. 
1 Chester, Frederick D. op. cit. 
