Habitat: Found in fertilized soil and in polluted water. 4. Vitreoscilla catenula Pringsheim, 1951. (Jour. Gen. Microbiol., 5, 1951, 130.) ca.te'nu.la. M.L. noun catenula a .small chain. Trichomes, 1.5 to 2.0 microns in diameter, may be cylindrical and of almost uniform width. Usually there are constrictions be- tween the cells, which are then barrel- shaped. The cells generally measure 3.0 to 4.0, sometimes up to 6.0, microns in length. The trichomes may break up into short fragments or grow to some length. Motile. Gram-negative. Gelatin: No liquefaction. Agar: Growth in curls without loose ends, otherwise similar to that of Vitreoscilla beggiatoides Pringsheim. Liquid media: Growth similar to that of Vitreoscilla beggiatoides. Casein not digested. Distinctive characters: The bead-like appearance of the cells is correlated with a greater tendency to break up into shorter lengths than is found in Vitreoscilla beg- giatoides. Verjr long trichomes are rarely found. Relationship to other species: Due to the constrictions between the cells, the tri- chomes resemble those found in the blue- green genus Pseudanabaena, especially P. tenuis Koppe. Source: Isolated several times from ditches between meadows in Cherry Hinton, Cambridge; later isolated from an infusion of cow dung from the same meadow. Habitat: Found in decomposing organic material. 5. Vitreoscilla paludosa Pringsheim, 1951. (Bact. Rev., 13, 1949, 72; also see Jour. Gen. Microbiol., 5, 1951, 133.) pa.lu.do'sa. L. adj. paludosus boggy, marshy. Trichomes 1.8 to 2.0 microns in diameter and very long, 300 and more microns in length. Subdivision occurs into cylindrical, often slightly curved, cellular sections, 30 to 70 microns in length, separated by deep constrictions at which they readily break. Branching sometimes occurs. Old cells con- tain spherical granules or droplets. Verj^ actively motile. Gram-negative. Gelatin: No liquefaction. Agar: Young aggregations, composed of parallel trichomes, grow to form elongated, slender, pointed, often Y-shaped colonies. Older colonies possess an inner concentric structure reminiscent of brain convolu- tions; flame-like processes at the edges grow out into long, curved and anastomos- ing tongues from which single trichomes emerge, commencing further systems of growth. Liquid media: Trichomes form a film on the glass surface or produce cotton-like floccules; sediment eventually produced. Casein not digested. Distinctive characters: Grows well and rapidly in liquid media. Not fastidious in food requirements. Relationship to other species: Growth on bacteriological agar is so luxuriant that it can scarcely be distinguished from that of Escherichia coli Castellani and Chalmers. Source: Isolated from material from the mill pond above Flatford Mill Field Centre, England. Habitat: Commonly found in decom- posing organic material. 6. Vitreoscilla stricta Pringsheim, 1949. (Bact. Rev., 13, 1949, 72; also see Jour. Gen. Microbiol., 5, 1951, 139.) stric'ta. L. part. adj. strictus drawn so as to have no slack. Rigid trichomes, 1.6 to 1.8 microns in diameter, relatively short, measuring up to 30 microns in length. The cells are, on the average, one and one -half times as long as they are wide. Terminal cells are rounded at the tip. The trichomes bend slowly and only to a small extent; true locomotion has not been observed. Generally the trichomes adhere to a surface with one end while the free end slowly oscillates. Gram-negative. Comment: This species has not been grown in pure culture. Source : Found in a pond with water fowl and in a pond polluted l)y cattle, both bodies of water containing iron organisms and a multitude of pigmented flagellates. Habitat : Found in fresh water containing decomposing organic material.
