Jan. 15,1917 
Blackleg Disease of Potato 
97 
not seen; flagella, 5 to 15 or more, peritrichously disposed; stained by Van Ermen- 
gem’s method; organism stained readily with the usual anilin colors; Gram’s method 
was negative, but positive with amyl alcohol; growth in agar abundant, filiform, 
spreading, elevation raised, luster glistening, opalescent; good persistent growth on 
potatoes, slightly raised and spreading, dull waxy and pale cream in color which 
subsequently changed to dirty white; growth in Loeffler’s blood serum good and 
slightly spreading, raised a little with the edges some higher than the center, waxy 
and pale yellow in color; uniform growth in gelatin stab cultures, filiform, liquefac¬ 
tion begins in 35 days and is not complete in 44 days; strong growth in nutrient 
broth+15 at25°C., slower at 2o°C.; ring in surface growth; clouding strong and 
persistent, fluid turbid, fine sediment; prompt coagulation of milk in 48 hours, 
extrusion of whey in 3 days, a few minute bubbles of gas visible; litmus milk acid, 
with partial slow reduction; growth in gelatin colonies slow, round to elliptical 
or egg-shaped in form; elevation, surface colonies flat; edge first entire, later lobate 
or erose; color faint brown by reflected, and bluish white by transmitted light; agar 
colonies round to lenticular, surface moist, shiny; elevation flat; edge entire; internal 
structure finely granular; growth in Fermi’s solution similar to that in Uschinsky’s 
medium, but slightly less in amount; copious growth in Uschinsky’s solution, ring, 
sediment, liquid appeared bluish; the best media for long continued growth was found 
to be beef bouillon and Uschinsky’s; in fermentation tubes gas was produced only in 
bouillon containing mannit and lactose; growth in the closed arm with production of 
acid in the presence of each of the following: Dextrose, saccharose, lactose, maltose, 
glycerin, mannit, and levulose; at the end of 10 days the closed arm with mannit, 
glucose, and lactose was clear, the other tubes remained clouded in the closed arm, 
but with less turbidity than was observed on the second day of growth; nitrates 
in nitrate broth were reduced, nitrites present; indol production moderate to feeble; 
growth in bouillon +16, Fuller’s scale, with hydrochloric acid and not at +18; growth 
in bouillon —16 with NaOH but not at —18; vitality on culture media, long; thermal 
death point 54 0 C., the optimum temperature 25 0 to 28°, slight growth at 37 0 , none 
at 42°; maximum temperature for growth 37.5 0 ; minimum temperature for growth 
about o°; in poured plates sensitive to sunlight, 90 per cent being killed in 30 min¬ 
utes and 100 per cent being killed in 50 minutes; pathogenicity proven in the follow¬ 
ing vegetables: Potato, tomato, Jerusalem artichoke, cucumber, red carrot, white 
carrot, radish, red beet (si.), sugar beet (si.), parsnip, cauliflower, cabbage, celery, 
mangel-wurzel, Swede turnip, and white turnip; also in living plants of potato, 
tomato, common red pepper, and slightly in cucumber and physalis. 
BACILLUS ATROSEPTICUS VAN HALL 
The description of this species was published in Dutch (15) as a part of 
a dissertation for the doctor’s degree. The following is based on a trans¬ 
lation of a part of this article, made for the writer by Dr. R. de Zeeuw. 
Bacillus occurring in 2-day-old bouillon cultures at 27 0 C., almost exclusively as 
single rods, sometimes in pairs; size variable, 0.8 to 1 ,6/jl long by 0.2 to 0.4^ wide, 
stained with gentian violet; many small zoogloea; very motile at 27 0 C. in young cul¬ 
tures containing 0.025 per cent of potassium phosphate and 0.25 per cent asparagin; 
flagella stained from such cultures by Loeffler’s method, length 10 to 15^; Gram’s 
stain decolorized. Growth weak on malt agar and malt gelatin; gelatin liquified, but 
rapidity is variable, does not take place on unneutralized meat gelatin and is some¬ 
times slight on one weakly alkaline. Strong coagulation of casein in milk. No 
diastasic action on starch. Gas production weak or absent except where mannit is 
used as a source of carbon. A medium consisting of “duinwater” (water out of the 
dunes, filtered through sand and gravel) plus 0.025 per cent of dibasic potassium phos- 
