xvi] VIBRIO AND SPIRILLUM 409 



pale pink or rosy colour. ^ It is motile, and forms a kind 

 of zooglcea, the individuals being closely placed and there- 

 fore producing a rosy colour of a more decided tint. Where 

 they form continuous masses, the naked eye can detect the 

 rosy tint. 



(g) Spirillum sanguimum {Ophidomonas sanguinea, Ehren- 

 berg). — This was observed by Cohn and Warming ^ in 

 pond-water. Morphologically it is identical with spirillum 

 volutans. It is motile, with a flagellum either at one or 

 both ends. Warming occasionally saw two and three 

 flagella at one end. It is about 3 /a thick ; all forms occur 

 between such as have half and such as have two and a half 

 turns of a spiral. Lankester also saw the same kind of 

 organism among his peach-coloured bacteria.^ 



(h) Spirillum rubrum (von Esmarch ^) forms long, very 

 motile spirilla, possessed of numerous flagella attached to 

 the sides of the spirilla ; it does not Uquefy gelatine. Its 

 colonies are of a deep red colour. 



(i) A variety of species of vibrios have been described 

 by Weibel ^ as occurring in sewage and on cultivation formed 

 coloured growths : vibrio aureus, flavescens and flavus ; none 

 of them liquefy the gelatine and are apparently not possessed 

 of motility. 



(J) Elwers and also Dunbar have isolated a vibrio or 

 spirillum phosphorescens which in cultivation has the 

 power to form phosphorescence ; it liquefies gelatine, and 

 is motile. 



(k) Dr. Lingard has found in, and I have isolated from, 



^ **Oii a Rose-coloured Spirillum,'' Quar. Journ. of Micr, Sci.^ 

 vol. XV. New Series. 



■^ Beitr. z. Biol. d. BJlanzen, vol. i. 



' Quarterly Jour, of Micr. Science, vol. xiii. New Series. 



^ Centralbl. f. Bakt. und Parasit., vol. i., p. 225. 



* Ibid., vol. iv., p. 258. 



