against various Gram-positive and Gram- negative bacteria, rickettsiae and the larger viruses. Comment : The type culture of this species was found in the culture bureau of Parke, Davis and Company, Detroit, No. 04745. A culture of this organism described by Umezawa and Maeda as a variety of Strep- tomyces phaeochromogenes is regarded by Waksman as identical with this species. (See Waksman, in Waksman and Leche- valier, Actinomycetes and Their Anti- biotics, Baltimore, 1953, 73.) Source: Isolated from soil in mulched field near Caracas, Venezuela. Habitat: Soil. 62. Streptomyces virgiiiiae Grundy et al., 1952. (Grundy, Whitman, Rdzok, Hanes and Sylvester, Antibiotics and Chemo- therapy, 2, 1952, 399.) vir.gi'ni.ae. M.L. noun Virginia Virginia; M.L. gen. noun virginiae of Virginia. Vegetative growth: Cream-colored to light brown on complex media; soluble, light brown, diffusible pigment. On syn- thetic media white to cream-colored growth with pink or grayish lavender aerial myce- lium. Undulating mycelium about 1 micron in diameter with short, thinner side branches. Aerial mycelium: Long, grayish pink or lavender aerial hj-phae. Most of the sporu- lating hyphae straight, occasionally a spiral is observed at or near the tip of the hypha. Spirals vary from tightly closed knots to loose, open spirals. Spores cylindrical, 0.75 to 1.0 by 1.1 to 1.5 microns. Gelatin: Gray to brownish surface pel- licle. Aerial mycelium thin, white. Soluble brown pigment extending as far as liquefied zone. Slow liquefaction. Agar: Sparse, white growth, turning cream-colored. White aerial mycelium, turning light grayish lavender when sporu- lation occurs. No soluble pigment. Synthetic glucose agar: Sparse, cream- colored growth. Aerial mycelium light grayish lavender. No soluble pigment. Glucose asparagine agar: Sparse, cream- colored growth. No aerial mycelium. No sporulation. No pigmentation. Ca-malate agar : Abundant, cream-colored growth. White aerial mycelium becoming tinged with grayish lavender. No soluble pigment. Starch agar: Thin colorless growth with aerial mycelium rose- to lavender-colored. Oatmeal agar: Abundant, cream-colored growth, turning golden brown. Abundant light rose aerial mycelium, turning lavender and gray. Soluble pale j-ellow pigment, turning light brown. Broth: Thin, cream-colored surface ring; a few flakes on bottom. Soluble brownish pigment. Milk: Brown growth. Milk becomes dark gray-brown or black. Not coagulated; slowly peptonized. Potato: Abundant, spreading, brownish growth. Aerial mycelium grayish lavender. Browning of potato. Starch is hydrolyzed. Glucose, mannose, galactose, maltose, starch, glycerol, sodium acetate and so- dium citrate are utilized. Xylose, lactose, sucrose, mannitol, sorbitol and potassium sodium tartrate are not utilized. Nitrites weakly produced, if at all, from nitrates. Optimum temperature, between 28° and 30° C. Antagonistic properties: Produces acti- thiazic acid. Source: Isolated from soil near Roanoke, Virginia. Habitat: Soil. 63. Streptomyces reticuli (Waksman and Curtis, 1916) Waksman and Henrici, 1948. (Actinomyces reticuli Waksman and Curtis, Soil Sci., 1, 1916, 118; Waksman and Henrici, in Manual, 6th ed., 1948, 944.) re.ti'cu.li. L. dim. noun reticulum a small net; L. gen. noun reticuli of a small net. Aerial mycelium: Whorls; spirals formed on glucose agar are sinistrorse. Conidia spherical, 1.0 to 1.4 microns in diameter. Gelatin stab: Liquefaction, with small, brown flakes. Agar: Gray, wrinkled growth, becoming brownish. Synthetic agar: Colorless growth, with
