434 



APPENDIX. 



b. Colouring matter green. 



(1) Bacillus pyocyaneus (Bacterium eeruginosum, Bacillus of blue or green 

 pus). On plates forms microscopical colonies, which send out radiating 

 threads and give rise to funnel-shaped liquefaction of the gelatine about the 

 second or third day ; the margin is clear and granular ; in tubes the gelatine 

 commences to liquefy at the surface in twenty-four hours ; there is a funnel- 

 shaped liquefying area limited to the neighbourhood of the needle-track, the 

 surrounding gelatine remaining solid, but assuming a beautiful fluorescent 

 colour ; on potatoes this organism grows as dry colonies with a dirty rusty 

 colour, the surrounding potato being stained slightly green ; if a drop of 

 ammonia is added to this, a green, if a drop of acid, a red colour is obtained ; 

 the organism grows extremely rapidly, and is strongly aerobic. It is a 

 very minute, short, thin rod, which is sometimes mistaken for a micro- 

 coccus ; does not form any spores. 



(2) Bacillus fluorescent liquefaciens (Grilngelber bacillus of the Germans]. 

 Is found in putrefying substrata, water, &c. ; colonies seen under lens are 

 at first circular, later have irregular outlines ; the centre is dark brown, 

 finely granular ; outside this is a transparent liquefying zone ; the whole 

 gelatine gradually becomes green ; in puncture cultures in gelatine a white 

 line is seen along the track of the needle, but near the surface there is a 

 little funnel-shaped depression, which gradually increases in size, a little 

 air-bubble frequently being formed near the surface ; the gelatine around 

 the liquid has a greenish-yellow fluorescent appearance, an appearance that 

 is not so marked in the liquefied gelatine itself ; on potatoes a yellowish- 

 brown layer is formed, around which there is slight discoloration of the 

 potato; the organism consists of a short active bacillus, arranged in pairs 

 and usually constricted in the middle. 



(3) Bacterium graveolens. Found in the fragments of epidermis taken 

 from between the toes ; obtained by Bordoni Uffreduzzi. Grows at the 

 ordinary temperature of the room on gelatine plates in the form of irregular 

 whitis-h-grey specks, which rapidly liquefy the surrounding gelatine ; these 

 give off the peculiar smell of the feet, and give rise to a greenish-yellow 

 coloration ; on potatoes grow very rapidly, and form a greyish mass with 

 an exceedingly offensive odour ; these organisms are about .8/t in length, 

 and nearly as broad as long. 



c . Colouring matter violet. 



Bacillus violacaus. Is found in water ; on plates it grows as small 

 round colonies, which liquefy the gelatine very rapidly ; these are first 

 white, but they very rapidly assume a beautiful violet colour, the mass sink- 

 ing to the bottom of the liquefied gelatine ; in tube puncture cultures the 

 gelatine is liquefied very rapidly, usually in a funnel shape, at the bottom 

 of which a beautiful violet granular mass collects, the liquefied gelatine 

 remaining clear ; the same beautiful colour is formed on agar-agar, potatoes, 

 and blood serum ; grows somewhat slowly and best at the ordinary tem- 

 perat ire of the room ; is a motile rod about four times as long as broad, 

 with rounded ends, and often contains spores ; it also grows out into 

 onger threads. 



III. Organisms do not grow on nutrient jelly, and only on 

 other media at higher temperatures and in the presence of 

 air. 



