i86 SULPHUR BACTERIA 



Cell-juicleiis. — The most remarkable feature in the cell is 

 a body which when stained with Delafield's haimatoxylin 

 exhibits a coloured centrum. This organ is regarded by 

 Hinze as the nucleus, and the coloured centrum as the 

 nucleolus. Hinze further stated that the nucleolus breaks 

 up into fragments before division and that nuclear division 

 follows the longitudinal cell division characteristic of this 

 organism, Hinze's figures are somewhat unsatisfactory, and 

 confirmation of his interesting statements is required. 



Thiovulum majus (Hinze). 



The cell is ellipsoid in form, and possesses a sharply 

 contoured membrane. Inside it, and penetrating in all 

 directions, are delicate plasma strings. In some cells the 

 plasma is massed at one of the ends, and a large vacuole 

 occupies the greater part of the cell. Chief among these 

 plasmatic inclusions are the sulphur globules, which are 

 soluble in 90 per cent, alcohol, and insoluble in hydrochloric, 

 nitric, and acetic acids. In the layer of protoplasm lining the 

 wall are found dull green, round, oval, or sometimes angular 

 plates, of varying size. They appear to increase in quantity 

 as the sulphur contents decrease, and are not present in all 

 individuals. Hinze regards them as reserve material, but 

 of a different nature from that found in Monas Mulleri. 

 They stain with Sudan, di-methyl-amido-azo-benzol, iodine 

 and methylene blue ; with Delafield's hsematoxylin they stain 

 a blue violet. The material is soluble in caustic potash, and 

 also in a I per cent, solution of nitric, sulphuric, and hydro- 

 chloric acids, but is insoluble in acetic acid. 



There are also in the plasma numerous small particles which 

 Hinze names " chromatin granules," and which react in a 

 similar manner to similar particles in Thiophysa volutans and 

 Beggiatoa alba to which he has given the same name. 



Chromatium Linsbaueri (Gicklhorn). 



An actively motile pinkish-red organism, ovoid in form, 

 and measuring up to i5/x in length. It grows in a pond in 



