Potato: Yellow to deep violet, rugose, spreading growth. Indole not produced. Usually no acid from glucose, maltose or sucrose. No acid from lactose. Nitrites produced from nitrates. Aerobic, facultative. Temperature relations: Optimum, 30° C. Good growth in 7 days between 2° and 4° C. No growth at 37° C. Comment: The most characteristic fea- ture of the original culture of this species was its ability to grow a heavy, folded, mem- branous pellicle on gelatin stabs and other media. The original culture also sometimes produced a metallic sheen. If the descrip- tions of all of the cultures regarded by Cruess-Callaghan and Gorman (Scientific Proc. Royal Dublin Soc, 21, 1935, 219) as C. amethystinum are taken into account, there really are no other important charac- ters by which this species can be separated from C. violaceum. Moreover, those that have studied many cultures of these violet organisms over a long period of time, with replatings to purify, report that this mem- branous growth may develop on almost any subculture of typical C. violaceum. The formation of this heavy, folded growth should therefore probably be regarded as a dissociation phenomenon. Further com- parative studies will presumably show that C. amethystinum should be regarded as a variant form of C. violaceum. Source: Isolated once by Jolles from spring water from Spalato. Habitat: Water. 3. Chroniobacterium janthinuni (Zopf , 1883) Holland, 1920. {Bacterium jan- thinum Zopf, Die Spaltpilze, 1 Aufl., 1883, 68; Holland, Jour. Bact., 5, 1920, 222.) jan'thi.num. Gr. adj. janthinus violet- colored. Rods, 0.5 to 0.8 by 1.5 to 5.0 microns, occurring singly. Motile with peritrichous flagella. Gram-negative. Gelatin colonies: Circular, yellow, be- coming violet. Gelatin stab: White to violet surface growth. Infundibuliform liquefaction. Agar colonies: Creamy center, violet margin. Agar slant: Yellowish, moist, gummy, glistening growth becoming deep violet. Broth: Turbid, with light violet pellicle. Litmus milk: Violet cream layer. Litmus decolorized from below. Rapid digestion. Potato: Violet to violet-black, spreading growth. Indole not produced. Acid from glucose. No acid from maltose, lactose or sucrose. Nitrites generally produced from nitrates. Aerobic, facultative. Temperature relations: Optimum, 30° C. No growth between 2° and 4° C. Grows well at 37° C. Source: Isolated from pieces of pig's blad- der floating on badly contaminated water. Habitat: Water and soil. This appears to be the species that causes a fatal septi- cemia in animals and man. 4. Chromobacterium niarismortui Elazari-Volcani, 1940. (Studies on the Mi- croflora of the Dead Sea. Thesis, Hebrew Univ., Jerusalem, 1940, VII and 76.) ma.ris.mor'tu.i. L. noun mare the sea; L. gen . noun maris of the sea; L. adj . mortuus dead; M.L. gen. noun marismortui of the Dead Sea. Rods, the length of which varies greatly with the concentration of salt and media. On agar media, in 3 to 24 per cent salt, the cells are usually 0.5 by 1.3 to 3.0 microns; in liquid media, 4.5 to 13.0 microns. Occur singly and in pairs. In 0.5 and 30 per cent salt and in Dead Sea water, the cells are usually very long, twisted threads. Motile by means of 4 to 6 peritrichous flagella. Gram-negative. Gelatin stab (12 per cent salt-1 per cent proteose peptone-15 per cent gelatin) : Fili- form, blue-brown, nailhead surface growth. Very slight infundibuliform liquefaction after six weeks. Agar colonies (12 per cent salt-1 per cent proteose peptone-2 per cent KNO3) : Circu- lar, smooth, entire, slightly convex and concentrically ringed with dark brown cen- ters followed by blue-brown, gray-brown and yellow rings and a colorless transparent margin. On removing the colony, a print remains in the agar consisting of three zones : a blue center, a brownish gray inner
