THE LEUCO-THIOBACTERIA 



127 



Thiospirillum Winogradskii (Omelianski). 



Literature. — Omelianski (2), 1905 ; Molisch (5), 1912. 



Ihis species was found in 1903 at the bottom of a high 

 glass vessel which had been filled with mud and water, from 

 the limans near Odessa, and to which some lime had been 

 added. It is a large, motile, colourless, or almost colourless, 

 spirillum, about 40/x long and 3-5/z thick, 

 as sketched by Omelianski (Fig. 20). The 

 normal form has one spiral turn but some 

 show two such turns. The single cilium, /<0- 

 which is probably compound, is polar. A^^'Qi 



Habitat.— Yownd in Russia (Omelianski) ; 

 Austria (Molisch) ; and Germany (Kolkwitz). 

 It is common in water, both fresh and salt, 

 containing hydrogen sulphide. 



Thiospirillum granulatum (Molisch). 



Literature. — Molisch (2), 191 2. 



An organism found in an artificial culture 

 containing fresh w-ater, mud, gypsum, and 

 roots of Elodea. This is a doubtful species, 

 as it was found in the same medium which 

 contained Beggiatoa alba and Cladothrix, both 

 of which are pleomorphic, and in some stages 

 have a spiral form. It is provisionally in- 

 cluded here. The length is given as 21 — 40/x 

 and its thickness 2 — 3"5/i.. 



^• 



^m 



Fig. 20. — 



Thiospirillum 

 Wiyiogradskii 

 (Omelianski) . 

 X 2500. 



Thiospirillum bipunctatum (Molisch). 



Literature. — Molisch (2), 1912 ; Wislouch (2), 1914. 



A marine organism showing a half, or a complete turn, with 

 a clear zone in the middle. The sulphur granules are located 

 in this middle portion. There is one cilium at each pole. 

 Volutin is present. Length of thread, 6-6 — lO/x, and thickness 

 1-9— 2-4/x (Fig. 21). 



