FAMILY VII. SPIRILLACEAE 229 



II. Crescent-shaped to spiral cells that are frequently united into spiral chains of cells. 



A. Cells not embedded in zoogloeal masses. 



1. Spiral cells with polar flagellation. 



a. Possess a tuft of polar flagella. 



Genus VII. Spirillum, p. 253. 

 aa. Possess a single, polar flagellum. 



Genus VIII. Paraspirillvm, p. 257. 



2. Crescent-shaped cells with a tuft of flagella attached to the middle of the concave 

 side of the cell. 



Genus IX. Selenomonas, p. 258. 



B. Crescent- to spiral-shaped cells embedded in a spherical mass of jelly. Found in 

 fresh water. 



Genus X. Myconostoc, p. 260. 



Genns I. Vibrio Miiller, 1773 * 



(Miiller, Vermium terrestrium et fluviatilum, 1, 1773, 39; Pacinia Trevisan, Atti d. Accad. 

 Fisio-Medico-Statistica in Milano, Ser. 4, 3, 1885, 83; Microspira Schroeter, 

 in Cohn, Kryptogamen-Flora von Schlesien, 3, 1, 1886, 168.) 



Vib'ri.o. L. v. vibro to move rapidly to and fro, to vibrate; M.L. mas.n. Vibrio that 

 which vibrates. 



Cells short, curved, single or united into spirals. Motile by means of a single, polar flagel- 

 lum which is usually relativel}^ short; rarely two or three flagella in one tuft. Grow well and 

 rapidly on the surfaces of standard culture media. Heterotrophic organisms varying greatly 

 in their nutritional requirements. Aerobic, facultative anaerobic and anaerobic species. 

 Widely distributed as saprophytic forms in salt- and fresh-water and in soil; also occur as 

 parasites and as pathogens. 



See Genus I, Pseudomonas, of Family IV, Pseudomonadaceae , for a discussion of the border- 

 line between the genus Vibrio and the genus Pseudomonas. 



Few comparative studies have been made on the species in this genus; it is therefore 

 impossible to prepare a really satisfactory differential key. 



The type species is Vibrio comma (Schroeter) Winslow et al. 



Kerj to the species of genus Vibrio. 



I. Aerobic species. 



A. Produce acid but no gas from glucose and usually from other sugars (one lumines- 

 cent, one halophilic and several agar-digesting species fail to produce acid from 

 glucose) . 



1. Not luminescent, not able to digest agar and do not attack benzene ring com- 

 pounds or o.\idize oxalates so far as known, 

 a. Found in fresh water or in the body fluids of animals, including man. 

 b. Liquefy gelatin. 



c. Indole produced. 



d. Nitrites produced from nitrates. 

 6. Milk not coagulated. 

 f. Cause of cholera. 



1. Vibrio comma. 



ff. Cholera-like vibrio from fresh water. 



2. Vibrio herolinensis. 



* Revised by Prof. Robert S. Breed, Cornell University, Geneva, New York, January, 

 1954; the section covering the microaerophilic and anaerobic animal pathogens was re- 

 viewed by Dr. E. V. Morse, College of Agriculture, University of Wisconsin, Madison, 

 Wisconsin, May, 1955. 



