128 



SULPHUR BACTERIA 



Habitat. — Found in mud from Trieste, in which hydrogen 

 sulphide was present. Also in mud from the harbour of Reval 

 (Esthonia). 



Thiospirillum agilissimum (Gicklhorn), Ellis. 



Literature. — Gicklhorn (i), 1920 ; Bavendamm, 1924. 



The generic name Spirillum was given to this organism by 

 Gicklhorn, and, following Wislouch, changed by Bavendamm 

 to Thiospira. 



A small S-shaped, or comma-shaped, spirillum, found in 

 mud samples from a pond at Graz (Poland). It measures 

 lOjx in length and about i-S — 2-C)/,i in thickness. Gicklhorn 



Fig. 21. — Thiospirillum 

 hipunctatum (Molisch). 



Fig. 22. — Thiospirillum agilissimum 

 (Gicklhorn), Ellis. X 3000. 



describes it as one of the smallest forms of sulphur-spirilla. 

 Its motility is very great. The sulphur droplets are pressed 

 close together, and number 4 to 1 2 in each cell. The membrane 

 is very delicate (Fig. 22). 



The introduction of hydrogen sulphide into the medium 

 containing the organism liad no apparent effect in promoting 

 growth. 



Thiospirillum agilis (Kolkwitz), Ellis. 



Literature. — Kolkwitz (3), 1909 ; Lauterborn (7), 191 5 ; 



Koppe, 1923 ; Bavendapim, 1924. 

 This organism was found in mud rich in hydrogen sulphide. 

 Its characteristics are given as follows : Thickness i/i, one 



