156 
Journal of Agricultural Research 
Vol. XXVI, No. 4 
Blood serum. —Growth is moderate, filiform, fiat, glistening, smooth. 
The medium is not liquefied. 
Milk. —There is no coagulation. Clearing begins in about a week and 
is completed in from four to six weeks. 
In one test, tubes 2 months old were a maize yellow (Ridgway) 8 
turning to brownish at the top. Other tubes 4 months old were a Sudan 
and Brussels brown (Ridgway). 
Litmus milk. —In 24 hours a blue rim shows at the top of the milk. 
In three days the inoculated tubes are all light blue and by the end of a 
week are colorless. 
Methylene blue with milk. —Tubes of milk containing methylene 
blue become colorless in 48 hours. 
Indol production. —Tests were made with sulphuric acid and sodium 
nitrite on cultures grown in Dunham’s solution for 1, 2, 4, 5, 9, and 12 
days. No indol was produced in this solution, nor in one made up with 
0.5 per cent disodium phosphate, 0.1 per cent magnesium sulphate, and 
1.0 per cent peptone in 100 cc. of distilled water. 
Hydrogen sulphid. —Hydrogen sulphid is produced by cultures on 
gelatin, beef-peptone agar, beef broth, and potato cylinders. The mar¬ 
gins of lead acetate paper were slightly darkened over gelatin, broth, 
and potato cylinders, and turned a dark brown over agar. 
Ammonia. —The production of ammonia is moderate. 
Nitrate reduction. —Nitrates are promptly reduced. Tests were 
made on cultures in nitrate broth with starch water, potassium iodid, 
and sulphuric acid. 
Fermentation tubes. —Cultures I, II, and V were grown in fermen¬ 
tation tubes containing a 1 per cent peptone solution to which was added 
1 per cent each of saccharose, lactose, maltose, dextrose, mannit, and 
glycerin. No gas was formed. Clouding was heavy in the open arm but 
no pellicle was formed. There was no clouding in the closed arm during 
the first few days. Tested with litmus paper the inoculated tubes were 
always alkaline whichever carbon compound was used. 
Loss op virulence. —Loss of virulence was slight in cultures carried 
for two years. 
Crystals. —Crystals are formed along the sides of the tubes in Uschin- 
sky’s solution, and occasionally in bouillon. 
Toleration op acids. —The proso organism grows promptly and 
well in neutral bouillon containing 0.1 per cent malic, tartaric, and citric 
acids, (P H 6.2) but does not grow at all in bouillon containing 0.2 per 
cent (P H 5.0-5.2) or 0.3 per cent (PH4.5-4.8) of these acids. 
Litmus sugar agar.— Cultures I and II grown on litmus sugar agar 
(2 per cent peptone, 1 per cent sugar, 1 per cent agar in distilled water) 
produced no acid with the following carbon compounds: Saccharose, 
lactose,, maltose, dextrose, galactose, mannit, arabinose, rafiinose. 
Reduction occurred with galactose, arabinose, and dextrose. 
Optimum reaction and toleration limits in bouillon. —The 
optimum reaction is +21 (P H 6.15) to +24 (P H 6.3). Toleration 
limits +33 (P H 5.4) and —22 (P H 10). 
Drying. —Dried smears on cover glasses usually live for five days, but 
cloud sterile broth slowly when dropped into it at the end of that time. 
Freezing. —Ninety-nine per cent were killed by freezing in salt and 
ice for 20 to 30 minutes. 
* Ridgway, Robert, color standards and color nomenclature. 43 P-. 53 col. pi. Washington, 
D. C. 19x2. 
