GENERAL SYSTEMATIC BACTERIOLOGY 475 



Ted. In the younger stages the organism appeared as a long oval, 

 like certain yeasts, but not more than 3 to 5^. Later the cells become 

 longer, narrower, rod-shaped, and finally spiral, similar to Spirillum 

 volutans. These spirals break up again into short bent segments, 

 somewhat more slender. Small ovoid bodies often develop. On the 

 death of the infected animal very numerous, small, strongly bent, 

 motile rods, which become Spiro7nonas-]ike, escape. At the ends of 

 these cells there develop strongly refractive swellings which were 

 regarded as spores. 



De Toni and Trevisan (1889, p. 1019) have included this organism 

 in their genus Pacinia. Their description of the organism reads: 



Baculis prima aetate magnis ellipsoideis, mox rectis, dein incurvis C3'lindricis, 

 apice rotundatis, demum in filamenta pseudospiralia consociatis; filamentis 

 postremo in baculos commae vel litterae S administar incurvis, minutissimos, 

 post Daphniae mortem uno apice arthrosporiferos solutis. In uUo medio nutri- 

 tivo huiusque adhibito non crescit. 



Certes (1889) described a giant spirillum as Spirobacillus gigas (ac- 

 cording to Zettnovv, 1903, p. 383) and later studied it in greater detail 

 (1900, p. 714). Zettnow also gives a description of this species. 



Blanchard (1906, p. 1) emended the diagnosis somewhat. He states: 



Bact^riacees de forme spiralee atteignant de grandes dimensions. Spores 

 endogenes. Pas de flagelles polaires, mais flagelles disposes, en petit nombre, 

 sur les cotes de chaque segment, comme ches les Bacillus. Deux especes acutel- 

 lement connues. Sp. cienkovskyi Metsclmikoff 1889. Sp. gigas Certes 1889. 



The genus is rejected as invalid by En^'in F. Smith (1905, p. 174) 

 And by Vuillemin (1913, p. 521), but is recognized by Meyer (1912, 

 p. 3). 



It is probably that this is a valid generic designation, but its exact 

 position and nomenclatural status is uncertain. 



Spirobacteria. The fourth tribe of bacteria recognized by Cohn 

 (1872, p. 180) as including the spiral or bent forms. Hansgirg (1888, 

 p. 264) used this for his first subfamily of his family Bacteriaceae. 

 Two genera were included, Spirochaete and Spirillum. The same 

 designation was also used by Blanchard (1906, p. 1) to include the 

 four genera Spirosoma, Vibrio, Spirohacillus and Spirillum. The 

 diagnosis given is: 



Bactdries plus ou moins incurvees en vis, I'incurvation ne formant dans d'au- 

 tres cas des tours de spire plus ou moins nombreux. Organisms peu ou pas flexi- 

 bles, se multipliant par division transversale. Formation de spores endogenes 

 constatee dans nombre d'esp^ces. 



