.^32 REMARKS ON PHOSPHORESCENT BACTERIA FROM SEA-WATER, 



I. 



The first kind appertaining to the above group of bacteria was 

 derived by me indirectly from sea-water, inasmuch as I obtained 

 it from dead marine fish, which were procured fresh at the 

 -Sydney Fish Markets, and which after some time became luminous 

 by themselves. From sea- water itself I have not succeeded yet in 

 cultivating it ; its regular appearance on various marine fish which 

 are being kept moist and at a moderate temperature, goes to show 

 that its habitat is sea- water. 



This microbe to which I have given the name of Bacillus smarag- 

 •dino-2)hosphorescens, forms, in its adult state, short thick rods of 

 about -001 mm. width, and is about double as long as wide. 



The extremities are rounded ofi". It is not motile and does not 

 show filaments so far as I could see. After treatment with 

 aniline dyes the bacilli are very distinctly seen to be stained only 

 at their peripheral parts, while a central spot, similar to a "vacuole," 

 x'emains unstained. 



They grow on and in nutrient gelatine without liquefying it. 

 Full particulars relative to their mode of growth will be given at 

 another time, here I may state that they spread themselves on the 

 gelatine but little, the ultimate size of their colonies being not very 

 considerable. 



The temperature at which this micro-organism develops best is 

 about 20° C. (68° F.), or a little higher, and it is then that the light 

 which its cultures emit is strongest. The colour of this light is a 

 wonderful emerald green. 



At temperatures between 13° C. and 15° C. (55r-59° F.) the 

 bacillus grows rathw slowly, and the emitted light is then less 

 •conspicuous and intense than that of cultures kept at the above 

 temperatures. 



Whether this bacterial species is identical with that described 

 by Dr. Fischer (I.e., pp. 92-95), and the Bacterium phosphorescens 

 of Dr. Hermes (I.e.), is still doubtful ; a satisfactory answer can 

 be arrived at when more information in consequence of continued 

 •observations shall be available. 



