124 
Journal of Agricultural Research 
Vol. VIII, No. 3 
Ammonia production, absent. 
Nitrates in nitrate broth reduced to nitrites. 
Indol production, moderate in old cultures, absent or feeble in young cultures. 
Toleration of acids. Grows in broth at +20 Fuller’s scale and not at +30 with hydro¬ 
chloric acid. 
Toleration of sodium hydrate, great. 
Optimum reaction for growth in bouillon in terms of Fuller's scale, o or slightly 
alkaline. 
Vitality on culture media. Relatively brief on agar and media containing carbo¬ 
hydrates; long on bouillon. 
Temperature relations. Thermal death point, approximately 46.5° C. Optimum 
temperature for growth, about 25 0 C. Maximum temperature for growth, about 
33 0 C. Minimum temperature for growth, below 5 0 C. 
Effects of drying. Readily killed. 
Exposure to sunlight. Exposure on ice at midday in November, slight diminution 
at 30 minutes, 100 per cent killed at 60 minutes. 
IV. PATHOGENICITY 
Virulent strains produce rapid decay accompanied by a pronounced blackening of 
the surface tissues when inoculated into young, growing potato stems; also causes 
a rapid softrot of potato tubers at moderate temperatures and may produce decay 
when inoculated into a considerable number of fleshy vegetables. 
LITERATURE CITED 
( 1 ) Appee, Otto. 
1902. Der Erreger der “Schwarzbeinigkeit” bei den Kartoffeln. In Ber. 
Deut. Bot. Gesell., Bd. 20, Heft 2, p. 128-129. 
(2) -- 
1902. Untersuchungen iiber das Einmiethen der Kartoffeln. In Arb. Biol. 
Abt. K. Gsndhtsamt., Bd. 2, Heft 3, p. 373-436, 8 fig., pi. 9. 
(3) :— 
1902. Zur Kenntniss der Bakterienfaule der Kartoffeln. In Ber. Deut. Bot. 
Gesell., Bd. 20, Heft 1, p. 32-35. 
(4) — 
1903. Untersuchungen fiber die Schwarzbeinigkeit und die durch Bakterien 
hervorgerufene Knollenfaule der Kartoffeln. * In Arb. Biol. Abt. K. 
Gsndhtsamt., Bd. 3, Heft 4, p. 365-432, 15 fig., pi. 8 (col.). 
( 5 ) - 
1904. Die Schwarzbeinigkeit und die mit ihr zusammenhangende Knollen¬ 
faule der Kartoffeln. K. Gsndhtsamt. Biol. Abt., Flugbl. 28, 4 p., 
illus. 
( 6 ) - 
1906. Biologie des Einmietens und Einkellems von Kartoffeln, Ruben und 
Gemfissen. In Lafar, Franz. Handbuch der technischen Mykologie. 
Aufi. 2, Bd. 2, Lfg. 12, p. 337-361, fig. 22-30. Jena. Literatur, p. 
360-361. 
( 7 ) - 
1906. Neuere Untersuchungen fiber Kartoffel- und Tomatenerkrankuhgen. 
In Jahresber. Angew. Bot., Jahrg. 3, 1904/05, p. 122-136, 2 fig. 
(8) Arbois dE JubainviixE, M. A. d’., and VesquE, Julien. 
1878. Les Maladies des Plantes Cultiv6es, des Arbres Fruitiers et Forestiers, 
Produite par le Sol, rAtmosph&re, les Parasites Vegetaux . . . 328 p., 
illus., 7 pi. Paris. 
