846 



ORDER VII. BEGGIATOALES 



B. Trichomes more than 2.0 microns in diameter. 



7. Vitreoscilla moniliformis. 



II. Trichomes more than 2.5 microns in diameter. Not cultivated in pure culture. 



A. Trichomes 4.0 microns in diameter. Sluggishly motile. 



8. Vitreoscilla conica. 



B. Trichomes more than 4.0 microns in diameter. Actively motile. 



9. Vitreoscilla major. 



1. Vitreoscilla beggiatoides Prings- 

 heim, 1949. (Bact. Rev., 13, 1949, 70; also 

 see Jour. Gen. Microbiol., 5, 1951, 127.) 



beg.gi.a.to.i'des. M.L. fem.n. Beggiatoa 

 a generic name; Gr. noun eidus shape, form; 

 M.L. adj. beggiatoides Beggiatoa-\ike. 



Cylindrical trichomes measuring about 

 2 microns in diameter, sometimes more or 

 less; length almost unrestricted, but under 

 less favorable environments the trichomes 

 may be as short as 10 microns. The tri- 

 chomes are composed of cylindrical units 

 showing constrictions which indicate the 

 locations of cell wall primordia. Motile. 

 Gram-negative. 



Gelatin: No liquefaction. 



Agar: Growth in curls, spirals and waves 

 with loose ends. 



Liquid media: Growth in trichomes of low 

 optical refraction. 



Casein not digested. 



Source : Isolated from a ditch with decay- 

 ing water weeds on Coldham Common, 

 Cambridge, where it occurred together with 

 Sphaerotilus discophorus, Beggiatoa alba and 

 many other organisms. 



Habitat: Found in quiet waters rich in 

 organic material and with black mud on the 

 bottom. 



2. Vitreoscilla stercoraria Pringsheim, 

 1951. (Jour. Gen. Microbiol., 5, 1951, 136.) 



ster.co.ra'ri.a. L. adj. stercorari^is per- 

 taining to dung. 



Trichomes 1.2 to 1.5 microns in diameter, 

 varying in length, measuring up to 100 mi- 

 crons. The trichomes may be composed of 

 rods of considerable length (12 microns and 

 more) or of cells which are not much longer 

 than they are wide. Above a certain length 

 the trichomes rarely remain straight but 

 bend irregularly forming aggregates like 

 curled hair. Motility is hesitant and slow. 

 Gram-negative. 



Gelatin: No liquefaction. 



Agar: Colonies are very dense and are 

 connected by a fine network; regular spirals 

 are formed. On rich media the colonies be- 

 come thicker and, after some time, yellow- 

 ish to translucent owing to autolysis of 

 cells. 



Liquid media: Growth at first filamentous 

 and loose; later becomes flocculent. 



Casein not digested. 



Distinctive character: Dense colonies 

 on agar connected by a fine network. 



Source : Isolated from dung. 



Habitat: Found in decomposing organic 

 material. 



3. Vitreoscilla filiformis Pringsheim, 

 1951. (Jour. Gen. Microbiol., 5, 1951, 130.) 



fi.li.for'mis. L. nomx filum a thread; L. 

 noun forma shape; M.L. adj. fliliformis 

 thread-shaped. 



Cylindrical trichomes, 1.2 microns in 

 diameter, of unlimited length, although 

 short trichomes are regularly present. Tri- 

 chomes pronouncedly more elastic and of 

 greater tensile strength than are those of 

 the other species in this genus. Both long 

 and short trichomes exhibit an active glid- 

 ing and swinging of the free ends. Gram- 

 negative. 



Gelatin: No liquefaction. 



Agar: Growth occurs in delicate, more or 

 less circular whirls and loops. 



Liquid media: Growth occurs near the 

 bottom or in tufts on the walls of the con- 



taining 



Casein not digested. 



Distinctive characters : Trichomes slender 

 and elastic. Growth on agar is in the form 

 of neatly rounded arches and loops as in 

 certain species of Oscillatoria. 



Source: Isolated from a crude culture 

 consisting of a grain of wheat covered with 

 soil and water from the pond in the Cam- 

 bridge Botanic Garden. 



