88 
West and Griffiths . — The Lime-Sulphur Bacteria 
aerated. If there is not sufficient oxygen, the organisms exude their 
globules of calcium carbonate, leaving a long double line of crystals of 
calcite as they move slowly about ; and subsequently death ensues. 
Comparison with Achromatium oxaliferum, Schewiakoff. 
The large bacterium Hillhousia resembles in some respects the organism 
described by Schewiakoff 1 as Achromatium oxaliferum , but differs in many 
particulars, which may be summarized as follows : 
Achromatium. 
Differentiation of protoplast 
into a peripheral zone with a small 
reticulum, and a larger central por- 
tion (‘ central body ’) with a much 
larger reticulum. 
Conspicuous reddish grains of 
chromatin (according to Schewia- 
koff) at the intersection of threads 
of central reticulum. 
Globules of calcium oxalate 
in the meshes of the reticulum. 
No sulphur grains. 
Average size : 29 /x x 15 /x. 
Hillhousia. 
No differentiation in the proto- 
plasmic reticulum. 
No definite chromatin recogni- 
zable by stains, but small granules, 
possibly of chromatin, in the threads 
of protoplasmic reticulum. 
Globules of calcium carbonate 
in meshes of reticulum. 
Refringent reddish grains of 
sulphur in threads of reticulum. 
Average size : 
Hillhousia mirahilis , 60 /x x 26/1. 
Hillhousia palustr is , 25 /x x 14/x. 
Eight years after the publication of Schewiakoffs paper, Massart 2 
described and figured an organism as Achromatium oxaliferum . He 
asserted that e en realite la couche peripherique de petits alveoles n’existe 
pas. . . . Je pense done que meme pour cette immense cellule il faut 
renoncer a l’espoir de trouver un corps central. 1 He also found that ‘ les 
petits grains tres refringents qui sont engages dans le reseau protoplasmique 
sont du soufre ’, and that ‘ (la cellule) contient une substance qui, contraire- 
ment a ce que dit M. Schewiakoff, n’est certainement pas de Facide oxalique 
ni un sel de calcium \ The size of the cell as figured is 30 /x x 20 /x. 
There is little doubt that the organism described by Massart was not 
Achromatium but Hillhousia palustris . The remarks on the structure of 
the protoplast and the inclusions are in agreement with our observations on 
1 W. Schewiakoff : Ueber einen neuen bakterienahnlichen Organismus des Siisswassers, Heidel- 
berg, 1893. 
2 Jean Massart : Recherches sur les organismes inferieurs. Sur le protoplasme des Schizophytes. 
Section C. Schizomycetes, b. Thiobact^ries, pp. 259-60, Plate I, fig. 7. Recueil de l’Inst. Botanique,' 
Univ de Bruxelles, tome v, 1901. 
