i62 - SULPHUR BACTERIA 



Genus i. — Rhodocapsa (Molisch). 



Literature. — Molisch (3), 1907 ; Bergey, 1923 ; Baven- 

 damm, 1924 ; 



One species found in Trieste marine water, containing de- 

 composing Zostera, to which it imparted a rose or peach-flower 

 colour. The organism is a rod-shaped, or sausage-shaped, 

 coloured bacillus. A shme capsule envelops each individual, 

 although during division there are temporarily several in- 

 dividuals in the same capsule (Fig. 39). The cells contain 

 peculiar structures called aerosomes, strongly refractive, 

 irregularly shaped, reddish bodies, the function of which, it 

 is claimed, is to keep the cell in suspension in the water. They 

 are also found in the Cyanophyceae. The cells also contain 

 sulphur granules. On liberation from the capsule, the cells 

 become motile, the movement being either a rapid rotation, 

 complete or partial, round a longitudinal axis, or rapid 

 oscillation of one of its ends. 



7 



Fig. 39. — Rhodocapsa suspensa. X 15. Fig. 40. — Rhodothece pendens. 



Rhodocapsa suspensa (Mohsch). 



Rod- or sausage-shaped, 3-5 — 180/A in length and 1-8 — 3-5/a 

 in thickness. Average length, 10 — 20fi. 



Genus 2. — Rhodothece (Molisch), 1906. 



Literature. — Molisch (3), 1907. 



A genus of one species, which was found in a crude culture 

 prepared from decaying animal remains, and sea-water, from 

 Heligoland. The organism coloured the water as though with 

 rose-red milk of sulphur. Like the preceding genus the cells 



