848 



ORDER VII. BEGGIATOALES 



7. Vitreoscilla moniliformis Prings- 

 heim, 1949. (Bact. Rev., 13, 1949, 72; also 

 see Jour. Gen. Microbiol., 5, 1951, 132.) 



mo.ni.li.for'mis. L. noun inonile a neck- 

 lace; L. nonn forma shape; M.L. adj. monili- 

 formis necklace-like. 



On plates the trichomes are in the form 

 of relatively large, streptococcus-like 

 chains. In mounted preparations the tri- 

 chomes measure up to 150 microns in length, 

 although generally they are only 30 microns 

 long. The trichomes are composed of a lim- 

 ited number of rod-shaped sections with 

 rounded ends which often appear to be sepa- 

 rated by short gaps; the trichomes, however, 

 move as a whole. The sausage-shaped sec- 

 tions are mostly j!^ to 2.5 microns wide and 

 are not very regular in form, often inflated 

 to a diameter of 2.8 to 3.0 microns, some- 

 times only a little longer than they are 

 wide; sometimes they measure 15 microns 

 in length and are elongated and cylindrical. 

 The cells tend to separate from each other, 

 and units of 4 to 5 cells are often found. 

 Long before division, the cells are marked 

 by constriction. Motility not very active. 

 Gram-negative. 



Gelatin: No liquefaction. 



Agar: Growth rather diffuse; the edges, 

 particularly on less rich media, are com- 

 posed of tongue-like processes while 

 rounded, twisted areas may be seen in the 

 interior of large colonies. 



Liquid media: Markedly turbid; later, a 

 sediment is formed. 



Casein not digested. 



Distinctive characters: Growth more 

 rapid and abundant than with the other 

 species of this genus. Not fastidious in food 

 requirements. 



Source: Isolated by Dr. C. F. Robinow 

 from cow dung. 



Habitat: Found in decomposing organic 

 materials. 



8. Vitreoscilla conica Pringsheim, 1951. 

 (Jour. Gen. Microbiol., 5, 1951, 139.) 



con'i.ca. Gr. adj. conicus conical. 



Trichomes about 4 microns wide and gen- 

 erally 20 to 50 microns in length. The cells 

 are slightly barrel-shaped and are filled with 

 refractive pseudo-granules. The terminal 

 cell is often longer than the other cells and 

 is attenuated near the tip. Not actively 

 motile. Gram-negative. 



Comment: This species has not been 

 grown in pure culture. 



Source: Described from mud from a pond 

 at Du Klip Vlei, Cape Flates, Cape Prov- 

 ince, South Africa, which had dried out 

 during the dry season and which was again 

 moistened in the laboratory. 



Habitat: Mud. 



9. Vitreoscilla major Pringsheim, 1951. 

 (Jour. Gen. Microbiol., 5, 1951, 138.) 



ma'jor. L. comp.adj. major larger. 



Trichomes relatively long and colorless, 

 6 to 7 microns in diameter, composed of 

 cells whose length (5 microns) is slightly 

 less than their width. A few refractive gran- 

 ules are found near the septa. The terminal 

 cells are in the form of flattened hemi- 

 spheres. As observed from the tip, the tri- 

 chomes rotate clockwise. Gram-negative. 



Comment: This species has not been 

 grown in pure culture. 



Relationship to other species: Morpho- 

 logically similar to the species in the genus 

 Thiothrix from which, however, it is dis- 

 tinguished by its continuous, active bending 

 and twisting. 



Source: Found in half -dried mud from a 

 ditch at Cherry Hinton, Cambridge, Eng- 

 land. 



Habitat: Mud. 



Genus II. Bactoscilla Pringsheim, 1949. 

 (Bact. Rev., 13, 1949, 72; also see Jour. Gen. Microbiol., 5, 1951, 144.) 



Bac.tos.cil'la. Bact- probably intended as a part of the stem of the Gr. noun bactrum a 

 staff, rod; L. noun oscillum a swing; M.L. fem.n. Bactoscilla oscillating rod. 



Very slender trichomes composed of rod-shaped cells apparently separated by empty 

 interspaces. Motile by means of a gliding movement. There is a slow, pronounced bending 

 of the trichomes at the joints, the individual cells remaining rigid. Gram-negative. Found 

 in fresh water containing decomposing organic matter. 



The type species is Bactoscilla flexibilis Pringsheim. 



