434 APPENDIX. 



b. Colouring matter green. 



(1) Bacillus pyocyanc us (Bacterium icr it ^inosum, 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 cerobic. It is a 

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

 coccus ; does not form any spores. 



(2) Bacillus fluorescens liquefaciens (Griingdber bacilhis 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 graveolcns. 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 

 whitish-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/x in length, 

 and nearly as broad as long. 



c. Colouring matter violet. 



Bacillus violacceus. 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. 



