278 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Bacterium phosphorescent, it imparts the phosphorescence. This "endemic 

 light-bacillus," as it is named, lias many points in common with Bacillus 

 phosphorescens, which is found in the West Indies. It consists of short 

 thick rods with rounded ends, and is endowed with lively movements. 

 In length they vary between 1 • 3-2 ■ 1 /a, and in breadth between 

 0*4-0 '7 fj.. They are usually seen lying in pairs, just having or just 

 ahout to divide. They stain with the ordinary anilin dyes. The rodlets 

 grow in ordinary gelatin, but better when 30 per cent, of salt or fish 

 gelatin is added. In plate-cultivations the surface of the gelatin is 

 eaten out into circular pits by the colonies, which, when young, are of 

 a pale sea-green colour, but as they increase in size assume a dirty 

 greyish-yellow hue. Tube-cultivations give a characteristic appearance 

 resembling a funnel at tho inoculation-place, and this at the end of the 

 first week is about 2 mm. wide and about 1 cm. deep. This bacillus 

 not only grows at ordinary temperatures, but also thrives at 5°-10° C, 

 and in this respect differs from the West Indian variety, which does not 

 develope below 15° C. The addition of salt to the gelatin accelerates 

 the growth, and while deprivation of air delays development, it does not 

 altogether prevent it. 



The light emitted from the cultivations of this bacillus is bluish- 

 white, not green like that of Bacterium phosphor escens. The light from 

 the cultivations is strongest from fresh ones and diminishes with age, 

 although after two months light is still visible in some tube-cultures. 

 At temperatures between 5-25° C. no marked difference was visible, 

 while higher degrees diminished the strength of the light. The addition 

 of salt to the gelatin was found to increase the intensity of the light. 

 Spectroscopic examination gave a continuous spectrum from D to some- 

 what beyond G, the maximum of brightness lying between E and the 

 middle of F and G. Colour differences were unrecognizable. Attempts 

 to photograph the colonies did not give very satisfactory results. 



Spirillum concentricum, a new species from decomposing blood * 

 — Dr. S. Kitasato premises that his Spirillum does not betray any patho- 

 genic characteristics. It was obtained from bullock's blood and culti- 

 vated on gelatin at a temperature of 20-22° C. On gelatin plates the 

 colonies appear as pale-grey discs formed of concentric rings, whence 

 their name. The spirilla grow on gelatin without liquefying it. In 

 test-tube cultivations they grow better on the surface than beneath. 

 On agar it would appear that the Spirilla grow not only along the 

 inoculation-track, but invade the adjacent parts, and the cultivation 

 adheres so closely to the surface that if an attempt be made to remove 

 any, the subjacent agar is torn away with it. On the whole, the growth 

 of the Spirillum was found to be more luxuriant at ordinary temperature 

 than in the incubator ; the most suitable being between 20° and 23° C. 



Microscopically, the Spirilla are short screws with two to three turns 

 and pointed ends. Cultivated in bouillon they grow to long screws 

 with five to twenty turns. The diameter is 2 ■ 0-2 ■ 5 p., and the length 

 of a turn 3 ■ 5-4 p. The thickness of the Spirilla is somewhat greater 

 than that of the cholera bacilli. In hanging drops upon hollow-ground 

 slides they exhibit lively wriggling movements like the Spirillum rubrum. 

 They stain well with the ordinary anilin dyes. No evidence of resting 

 forms was found. Mice, guinea-pigs, and rabbits were not affected by 

 injections of the pure cultivations. 



* Centralbl. f. Bakteriol. u. Parasitenk, iii. (1888) pp. 73-5. 



