I50 SULPHUR BACTERIA 



forma minus, chiefly on account of the characteristic massing 

 of the sulphur globules at one of the poles. He therefore 

 regards this organism as one potentially capable of developing 

 colouring matter, for Chromatium Warmingii forma minus 

 is the organism which was artificially cultivated by Baven- 

 damm, and in such cultures the colouring matter was richly 

 developed. 



Fig. 32. — Chromaiiitm cuculliferum. X Oooo. 



Rhabdomonas and Rhabdochromatium. 



Literature. — Cohn (10), 1875 ; Warming, 1875 ; Zopf 

 (l), 1882 ; Mitrophanow, 1893 ; Zopf (3), 1895 ; 

 Biitschli (4), 1902 ; Nadson (2), 1903 ; Kolkwitz (3), 

 1909; Lauterborn (7), 1915 ; Gicklhorn (2), 1921 ; 

 Bergcy, 1923 ; Bavcndamm, 1924. 



The term Rhahdomonas is of early origin, and was employed 

 by Cohn to designate those members of the Chromatium. group 

 which arc rod- or spindle-shaped. Rhahdomonas resembles 

 Chromatium in every respect except in shape. When the genus 

 Chromatium was transferred from the Flagellates to the Bacteria, 

 necessitating the discarding of the name Monas, the name was 

 changed to Rhabdochromatium. This term is now in general 

 use, although Bergey in his classification reverts to the older 

 name Rhahdomonas. As has already been shown (see pages 

 138-139) this peculiar shape of organism is linked up with the 

 normal Chromalimn by a very large number of transitional 

 forms, and so it cannot be regarded as a distinct species. 



