sine, 1-cystine, d-glutamic acid and yeast extract can be used as a source of nitrogen (Pinckard, loc. cit.). Temperature relations: Optimum, 28° C. Minimum, 8° C. Maximum, 36° C. (Pinck- ard, loc. cit.). Distinctive characters: Differs from Agro- bacterium tumefaciens in that it does not utilize nitrates and grows much more slowly on ordinary media. Infects only members of the genus Rubus. Starr and Weiss (Phyto- path., 33, 1943, 317) state that this species, unlike Agrobacterium tumefaciens and Agro- bacterium rhizogenes, does not utilize as- paragin as a sole source of carbon and nitro- gen. Source: Isolated from raspberry canes, Rubus spp. Habitat: Pathogenic on black and purple cane raspberries, on blackberries and, to a lesser extent, on red raspberries. 6. Agrobacleriuni radiobacter (Bei- jerinck and van Delden, 1902) Conn, 1942. {Bacillus radiobacter Beijerinck and van Delden, Cent. f. Bakt., II Abt., 9, 1902, 3; Conn. Jour. Bact., 44, 1942, 359.) ra.di.o.bac'ter. L. noun radius a ray, beam; M.L. bacter masculine equivalent of Gr. neut.n. bactrum a rod or staff; M.L. mas.n. radiobacter ray rod. Small rods, 0.15 to 0.75 by 0.3 to 2.3 mi- crons, occurring singly, in pairs and, under certain conditions, in star-shaped clusters. Motile with one to four flagella. Prevail- ingly Gram-negative, but an occasional culture is variable. Nutrient gelatin stab: No liquefaction. Agar slant: Flat, whitish slimy layer. Mannitol - calcium - glycerophosphate agar streak plates: Abundant, raised, slimy growth surrounded by a brown halo w'ith an outer zone of white precipitate (Riker et al.. Jour. Agr. Res., 41, 1930, 524). Broth: Turbid; heavy ring or pellicle if veal infusion is present. Litmus milk: Serum zone with pellicle in one week; usually turns a chocolate- brown in 2 weeks; same in plain milk, but with less browning. Potato: Raised slimy mass becoming brownish; potato may be browned. Starch not hydrolj'zed. No organic acid or visible gas from sugars ; nearly all sugars, glycerol and mannitol are utilized with the production of CO 2. Nitrates completely assimilated; test for nitrites may be negative (Hofer, Jour. Bact., 41, 1941, 202). Temperature relations: Optimum, 28° C. Minimum, near 1° C. Maximum, 45° C. Aerobic. Media containing KNO3, K2HPO4 and glycerol, ethanol or propanol become alka- line to phenol red (Sagen, Riker and Bald- win, Jour. Bact., 28, 1934, 581). Growth occurs in special alkaline media of pH 11.0 to 12.0 (Hofer, Jour. Amer. Soc. Agron., 27, 1935, 228). Hydrogen sulfide produced if grown in ZoBell and Feltham's medium (ZoBell and Feltham, Jour. Bact., 28, 1934, 169). Distinctive characters: Browning of man- nitol-calcium-glycerophosphate agar; in- ability to cause plant disease or to produce nodules on roots of legumes; complete uti- lization of nitrate (the nitrate disappears) in the peptone-salt medium of Riker et al. (Riker et al., Jour. Agr. Res., 4I, 1930, 529) and failure to absorb congo red (Riker et al., ibid., 528). This species bears at least superficial resemblances to certain Rhizobium spp. but may be distinguished from them by the first two characters listed above and by the following in addition: Growth at a reaction of pH 11 to 12; heavy ring or pel- licle formation on veal infusion broth; hy- drogen sulfide production in the mannitol - tryptone medium of ZoBell and Feltham (ZoBell and Feltham, op. cit., 1934, 169); production of milky white precipitate on nitrate-glycerol-soil-extract agar. Source: Isolated from soil. Habitat: Soil around the roots of plants, especially legumes. 7. Agrobacterium stellulatum Stapp and Knosel, 1954. (Zent. f. Bakt., II Abt., 108, 1954, 244.) stel.lu.la'tum. L. noun stella star; M.L. adj. stellulatus resembling a small star. Rods, 0.2 to 0.8 by 0.3 to 2.1 microns, oc- curring singly or in pairs; in certain media, star-like clusters are found. Motile by means
