860 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



1926, 165). The account of this pleo- 

 morphic organism, which is claimed to 

 multiply by fission, budding, and prob- 

 ably spore formation, is wholly uncon- 

 vincing. The shape and size of some of 

 the cells make it appear likely that Ellis 

 observed mixtures of various kinds of 

 purple sulfur bacteria. 



Illustrations: I^llis, loc. cit., 166, 

 fig. 1-14; 171, Micro. I; 172, Micro. II; 

 Sulphur Bacteria, London and New 

 York, 1932; 153, fig. 33; 151, fig. 34; 156, 

 fig. 35; 158, fig. 36. ^ 



Penally, there exist some, as yet un- 

 named, red to purple bacteria which con- 

 tain bacteriochlorophyll and carotenoid 

 pigments, are capable of photosynthesis 



in the presence of hydrogen sulfide, but 

 excrete elementary sulfur as an inter- 

 mediate oxidation product instead of 

 storing sulfur globules inside their cells 

 (van Niel, Arch. f. Mikrobiol., 3, 1931, 

 63) . They are small motile rods, vibrios 

 or spirilla, about 0.5 by 1 to 2 microns. 

 They may also occur as spherical cells 

 of about 1 micron in diameter. They 

 can readily be grown in organic media, 

 under anaerobic conditions, in illumi- 

 nated cultures and may be included 

 either with the sulfur purple bacteria or 

 with the non-sulfur purple bacteria, 

 among which Rhodopseudontonas palus- 

 Iris is equally capable of photosynthesis 

 in the presence of reduced inorganic sul 

 fur compounds. 



