452 MICRO-OKGANISMS IN WATER 



BACILLUS PHOSPHOEESCENS INDIGENUS 



LIQUEFIES GELATINE 



Autlxority. — Fischer, ' Ueber eineniieuen lichtentwickelnden Bacillus,' Cen~ 

 tralhlatt filr Bakteriologie-, vol. ii., 1888, p. 105. See also Katz, ' Zur Kenntniss 

 der Leuchtbakterien,' Centralblatt f. Bakteriologie, vol. ix., 1891, p. 159. 



Where Found. — In sea-water in the harbour of Kiel ; also obtained from the 

 bodies of green herrings. As many as from four to twenty individuals were 

 found in 1 c.c. of the harbour water. 



Microscopic Appearance. — Short fat bacillus, resembling the B. phos. indi- 

 cus (p. 451), but somewhat shorter. Their length varied between 1-3 and 2*1 fi, 

 and their breadth between 0-4 /i and 0-7 fi. Occurs mostly in twos ; forms also 

 threads. It is very motile. 



Cultures.^ Grows best on herring gelatine {i.e., green herrings substituted 

 for beef and gelatine). If a small spot of a cooked green herring is inoculated 

 with the bacillus the whole fish becomes covered in a few days with a greyish 

 white slimy material, which exhibits phosphorescence in the dark. By adding 

 common salt to ordinary culture gelatine the growth of the bacillus is not only 

 stimulated, but it becomes more phosphorescent. 



Gelatine Plates. — A depression is visible after a few days in the vicinity of 

 the bacillus, and in about seven days a thm dirty yellow disc is seen lying at 

 the bottom of it. Under a low power the smaller colonies are circular and 

 smooth-rimmed, of a pale sea-green colour. Older colonies have a dirty greyish 

 yellow colour, and a pinkish tinge is usually visible near the edge of the 

 colony. The liquefaction of the gelatine takes place more slowly than in the 

 case of B. phos. indicus. 



Gelatine Tubes.— In about a week a narrow funnel-shaped hquid depression 

 is visible about 2 mm. wide, and filled with air to about a depth of 1 cm., 

 below which are flocculent and crumbly growths surrounded by a very little 

 liquid. The depression becomes later deeper, but not much wider, and the 

 liquid gelatine in old cultures has almost entirely disappeared. 



Potatoes and Blood Sekuji. — No gi'owth. 



Remarks. —The brilliancy of the phosphorescence is not so great as in the case of 

 the B. phos. indicus. If some of the cultm-e material be added to sea water, the 

 latter phosphoresces in the same manner as ordinary phosphorescent sea-water. It 

 is not pathogenic. 



