RHODO-THIOBACTERIA 167 



number of small cocci, each containing one sulphur granule. 

 The coccus is roughly spherical (about l\yL in diameter) and 

 is devoid of a membrane. An opportunity has not arisen to 

 follow the life-history of this interesting species. 



Genus 3. — Thiosph.^rion (Miyoshi). 



Literature. — Miyoshi, 1897 ; Migula (3), 1897 ; Bergey, 

 1923 ; Bavendamm, 1924. 



Description. — The outstanding feature of this genus of only 

 one species is the exactly spherical shape of the colonies, and 

 their violet colour. Migula and Bavendamm included the 

 genus in the Lamprocystece. Bergey removed it from this 

 group, and once more gave it generic status. The exactly 

 spherical solid masses of slime of a violet colour, arranged in 

 little groups in attachment to objects in the water, appear 

 to offer a sufficient distinction to merit generic rank. 



Thiosph.erion viol ace a (Miyoshi). 



Cells are spherical-ellipsoidal, 2-5 — i*8jLt, and violet in 

 colour. Sulphur inclusions are somewhat angular (Fig. 43a). 



Habitat. — Sulphur springs in Japan. Found on threads 

 of Thiothrix. 



Note on the Organism Thiosphjera gelatinosa (Miyoshi). 



Literature. — Miyoshi, 1897; Migula (3), 1900 ; Bergey, 

 1923 ; Bavendamm, 1924. 



All that is known of this organism is that it is made up of 



ovoid cells (7/x X 5ju,) enveloped in a loose jgr-^i^jr*^-^ 



gelatinous envelope. Migula and Baven- ^ -n 



damm placed it in the Lamprocystece, l' ®®®^ ® \ 



whilst Bergey gave it generic rank. As \- '^ (^ ^ ® '\ 



so little is known, and what is known is %. ®®(^^ ^| 



a condition that may be a phase in %l:? '^■'^- -.J^ 



the life cycle of one of several organisms, •^■<i^-u-^ 



r 1 • 11-, Fig. 44. — Thiosphcsra 



no useful purpose is served by its re- 7 .■ 



^ ^ J gelatinosa. 



tention (Fig. 44). 



