518 MICRO-ORGANISMS IN WATER 



STKEPTOTHBIX FOERSTEBI (Colin) 



| LIQUEFIES GELATINE j 



Authority. Gombert, Bcchcrches expgrim. sur les Microbes des Conjonc- 

 tives a VEtat normal, Montpellier, 1889. Also Almquist, ' Untersuchungen 

 ueber einige Bacteriengattungen mit Mycelien,' Zeitschrift /. Hygiene, vol. viii., 

 1890, p. 195. Also Gasperini, ' Recherches morph. et biol. sur un Microorgan. 

 de 1' Atmosphere, le Streptothrix Frersteri,' Ann. de Micrographie de Miqucl, 

 July and August, 1890. Also G. Roux, Precis d' Analyse microbiologique des 

 Eaux, Paris, 1892, p. 369. 



"Where Found. Found first in the concretions of the lachrymal duct by 

 Fcerster, Cohn, &c. ; it has also been found in air, and in salt and fresh water by 

 Almquist and Roux. Koux assumes the Streptothrix found in water by him 

 and Almquist to be identical with that described by Gombert. Almquist states 

 that his Streptothrix did not liquefy gelatine. 



Microscopic Appearance. Long filaments with rounded ends, rectilinear, or 

 more often undulatory or spiral-shaped. From 0-5 p. to 0-6 Abroad and extremely 

 variable in length, from 4 yu and 6 /J. to 92 /j., and sometimes longer. Forms spores 

 0'8 fj. in diameter. Not properly motile. (Gombert.) 



Cultures. 



GELATINE PLATES. Forms in four or five days small greyish white cloudy 

 spots in the depth of the gelatine. They have an opaque dark grey centre, 

 whilst the periphery is white and semi-transparent. The gelatine is depressed 

 in the vicinity of the colony. On endeavouring to detach a portion of the 

 colony with a platinum needle the whole is removed. Under a low power they 

 are blackish in colour, and the periphery consists of a number of short, irregular, 

 and stiff hairs, recalling the appearance of a chestnut in its spinose capsule. 

 The surrounding gelatine does not become brown, as is characteristic of the 

 growth of Cladothrix cultures. Slow liquefaction of the gelatine ensues. 

 (Gombert.) 



AGAK-AGAB. Grows abundantly and rapidly at both 20 and 37 C. A 

 whitish thin crust forms over the growth, which loses at once its white colour 

 when washed over with liquids. (Almquist.) 



BKOTH. Forms at the end of a few days at 37 C. white spinose spherules, 

 which float in the liquid or attach themselves to the walls of the tube. The 

 liquid remains clear and becomes slightly darker, but never assumes the brown 

 tint characteristic of Cladotlirix dicliotoma. (Gombert.) 



STEKILISEJ) TAP-WATER. Grows fairly well. 



Remarks. Not pathogenic to animals (Gombert, Gasperini, and Eoux). 



