4&o 
Journal of Agricultural Research 
Vol. XXVI, No. 10 
Agar plates. —The surface colonies on plain agar form rapidly, measuring i mm. 
within 24 hours and 5 mm. within 1 week. The outline is circular and entire, and 
the surface is oval and glistening. By reflected light the growth is gray with an 
opaque center becoming translucent toward the border; by transmitted fight it is 
bluish gray. Magnified, the colony is brownish with a more or less uniformly granular 
structure. The bacterial mass is nonviscid and adheres to the medium. 
Gelatin plates. —In 24 hours at room temperature the colony is surrounded by 
a small area of liquefaction. 
Agar slant.—A slightly raised, bluish gray, friable growth of moderate amount 
and limited to the surface inoculated is present in 24 hours. Old cultures show a 
light yellowish brown tint. 
Gelatin stab. —At room temperature in 24 hours there is a moderate white growth 
along the line of puncture with beginning liquefaction. This proceeds slowly, 
being greater at the surface, becomes crateriform to infundibuliform, and is complete 
within three weeks. At lower temperatures the growth and liquefaction are slower. 
Potato. —In one day there is a feeble, moist, slightly yellowish growth which 
increases and becomes medium in quantity later and of a Drownish hue. The potato 
is discolored. 
Bouillon. —Growth takes place rapidly, becoming slightly clouded in 4 hours and 
turbid in 24. A very thin, delicate pellicle may form and much friable sediment is 
present in old cultures. The medium remains clouded. 
Milk. —No change is apparent during the first two days. A coagulum is present 
on the third day; by the end of a week 1 cm. of this is digested; and by the end of one 
month one-half is dissolved, leaving a brownish, turbid, slightly viscid whey. 
Litmus milk. —The medium appears unchanged on the first day, becomes alkaline 
on the second, and continues to be so. 
Carbohydrates. —A carbohydrate as a rule enriches a medium. Fermentation 
with acid occurs in dextrose, levulose, galactose, mannose, maltose, saccharose, 
lactose, glycerin, mannite, arabinose, xylose, dextrin, and in the glucoside salicin. 
From lactose and arabinose only a slight amount of acid was produced within 24 
hours, the medium changing to alkaline during the second or third day. No acid was 
formed in raffinose, inulin, and erythrite. Gas is produced in small quantities in 
glucose, levulose, mannose, saccharose, salicin, and possibly occasionally in other 
media. 
Sugar-free bouillon. —No indol is produced. 
Blood-agar plates. —No hemolysis occurs on blood agar made from whole rabbit’s 
blood. 
FURTHER EXPERIMENTAL INOCULATION 
A variety of preliminary inoculation experiments were performed to 
determine further the nature of homworm septicemia. Some of these 
are summarized here. In the following group homworms were used 
and the inoculations were made by puncture: In 12 experiments, 76 
larvae were inoculated using the tissues of worms dead less than 24 hours 
of homworm septicemia. All of these died of the disease. In two 
experiments, 15 larvae were inoculated with disease material from worms 
which had been dead two or three days. Only one of these became 
infected and died. In four experiments 34 larvae were inoculated using 
a pure culture of Bacillus sphingidis. Of these 33 became infected and 
died. 
In another group the feeding method of inoculation was employed. 
In two experiments using 34 larvae, the disease material was obtained 
from worms dead less than one day of homworm septicemia. Of these 
6 died of the disease. In two experiments in which 12 larvae were used, 
worms dead from two to five days furnishing the disease material, none 
died. In two experiments 20 larvae were fed pure cultures of Bacillus 
sphingidis and of these 2 died of homworm septicemia. In two experi¬ 
ments, the body wall of the 20 larvae used was first pierced in several 
places with a sterile needle and then the worms were fed leaves which 
had been dipped into an aqueous suspension of crushed tissues of worms 
