diameter, round, smooth, moist, slimy, orange to rust-red. Coagulated blood serum: No liquefaction. Litmus milk: Distinct alkalinity after 10 days. Indole not produced. Hydrogen sulfide not produced. No acid from carbohydrate media. Starch not hydrolyzed. Acetj'lmethylcarbinol not produced. Nitrites not produced from nitrates. Ammonia produced in peptone media. Urea not hj-drolyzed. Blood agar: No hemolysis. Aerobic. Optimum temperature range, 15° to 22° C. Optimum pH, 6.4. Source: Isolated from the medicinal leech (Hinido niedicinalis). 18. Corynebacteriuni insidiosum (Mc- Culloch, 1925) Jensen, 1934. (Aplanobacter insidiosum 'SicCulloch, Phytopath., 15, 1925, 497; also see Jour. Agr. Res., 33, 1926, 502; Jensen, Proc. Linnean Soc. New So. Wales, 59, 1934, 41.) in.si.di.o'sum. L. adj. insidiusus deceit- ful, insidious. Rods, 0.4 to 0.5 by 0.7 to 1.0 micron. En- capsulated. Non-motile. Gram-positive. Gelatin: Slow liquefaction. Beef agar colonies: Pale yellow, circular, smooth, shining; edges entire; viscid. Blue granules found on the medium. Milk: Coagulated after 16 to 20 days. No digestion. An apricot-^yellow sediment is deposited on the walls of the tube. Indole not produced. Hydrogen sulfide not produced. Acid from glucose, sucrose, lactose and glycerol. Moderate diastatic action. Nitrites not produced from nitrates. Grows in 5 per cent salt. Aerobic. Optimum temperature, 23° C. Maximum, 31° C. Distinctive character: Bluish granules produced in culture. Comments: Jensen (ibid., 42) reports that he has found a non-infectious variety of this species in grass land soil in Australia. Source: Isolated from diseased alfalfa plants. Habitat: Vascular pathogen of alfalfa, Medicago saliva . 19. Corynebacteriuni sepedonicum (Spieckermann and Kotthoff, 1914) Skap- tason and Burkholder, 1942. {Bacterium sepedonicum Spieckermann {nomen nudum), 111. Landw. Zeitung, 33, 1913, 680; Bacterium sepedonicum Spieckermann and Kotthoff, Landw. Jahr., 46, 1914, 674; Skaptason and Burkholder, Phytopath., 32, 1942, 439.) se.pe.do'ni.cum. Gr. adj. sepedonicus leading to decaj'. Description taken from Stapp (Ztschr. f. Par., 5, 1930, 756). Rods 0.3 to 0.4 by 0.8 to 1.0 micron. Pleo- morphic. Non-motile. Gram-positive. Gelatin: Liquefaction slight. Agar colonies: Thin, smooth, translucent, glistening, whitish, 2 to 3 mm in diameter. Broth: Weak growth. No pellicle. Light sediment. Litmus milk: Little change in 6 weeks, after which litmus is reduced. Indole not produced. Hydrogen sulfide production feeble, if at all. Glucose, galactose, fructose, arabinose, xylose, mannitol, glycerol and dulcitol are utilized. Starch hydrolj'sis light. Grows in 4 per cent salt. Temperature relations: Optimum, be- tween 20° and 23° C. Minimum, 4° C. Max- imum, 31° C. Distinctive characters: Differs from Co- njnebacterium michiganense in that it is white to cream-colored on various media and has a lower optimum temperature. Corynebacterium michiganense does not in- fect potatoes. Source: Stapp used 17 cultures isolated from diseased potatoes. Habitat: Causes ring rot of ])otato tubers in Germany. 20. Corynebacteriuni huniiferuni Selis- kar, 1952. (Colorado Farm and Home Re- search, 2, 1952, 9.) hu.mi'fer.um. L. noun humus soil; L. v. fero to bear; M.L. adj. humiferus soil-borne.
