APPENDIX. 427 



in putrifying flirds. Grows on plates, in the deeper layer of the gelatine 

 only, as exceedingly slowly growing delicate white clouds ; along the track 

 of a needle culture delicate, branching, almost cloud-like growths are seen, 

 which are always more marked in the deeper part of the tube than in the 

 upper part. (N. B. If the gelatine is exceedingly alkaline there may be slight 

 liquefaction of the medium.) On agar-agar, pale yellow sharply-defined 

 colonies are formed. The organism is non-motile, is exceedingly small, 

 being only about ifi in length and from .1 to. 2/j, in thickness ; two of them 

 are frequently adherent to one another ; they contain spores. Mice 

 inoculated die in from 40 to 60 hours when bacilli are found in the 

 blood, especially in the capillaries of the kidneys and spleen. 



(3) Bacillus of swine erysipelas (Schwein Rothlauf}. Has been obtained 

 from the spleen and blood of pigs that have died from this disease. It is 

 extremely like the previous organism except in the following points : The 

 cloudiness in the needle culture is not quite so diffuse, and the bacilli are 

 slightly longer and thicker ; causes death of mice in from 2 to 3, pigeons 

 in from 3 to 4, and rabbits in 6 days ; is also fatal to pigs. 



B. Colonies colourless, nutrient substratum near growth stained. 

 a. Substratum stained greenish. 

 (3. ,, blue or greyish brown, 



y. violet, see p. 428. 



a The substratum is stained greenish. 



(1) Bacillus fluorescens putidus. Obtained from putrefying fluids. 

 In the deeper layers of gelatine plates it forms small dark colonies. 

 At the surface it appears as round wafers with irregular outlines ; the 

 surrounding gelatine has a peculiar greenish fluorescent appearance ; in 

 needle cultures there is distinct cloudiness along the needle track and green 

 coloration of the gelatine, which is always more marked when oxygen has 

 access to the growth ; strong herring brine odour ; grows rapidly on 

 potatoes, forming a thin brown or greyish layer ; is a short, thin, very motile 

 bacillus with rounded ends. 



(2) Bacillus erythrosporus. Obtained from putrefying albuminous 

 fluids, drinking water, &c. Occurs on plates as whitish colonies, which 

 gradually spread over the surface ; around them in the gelatine a peculiar 

 fluorescence appears ; the centre of the colony is usually opaque and 

 brownish, the outer zones are light yellowish green, not so opaque, and 

 there is a slight radiate marking ; along the needle track and at the surface 

 is a well-marked growth ; the surrounding gelatine is green by transmitted, 

 and yellow by reflected light ; on potatoes forms reddish or nut-brown 

 localized patches ; grows moderately quickly, especially at the ordinary 

 temperature of the room ; occurs as slender bacilli with slightly rounded 

 ends, single or in threads ; in these threads are from two to eight dirty red 

 spores, which are very distinctly seen, sometimes have almost the appearance 

 of a string of beads. 



(3. The substratum it stained blue or greyish brown, 

 (i) Bacillus cyanogenus (or Blue milk bacillus). On gelatine plates 

 forms rounded, dirty white, finely granular colonies with smooth outlines ; 

 the surrounding gelatine takes on a light green or greenish brown colour ; 

 in a needle culture in gelatine it has the " nail " appearance, with 

 a milk white head, the surrounding gelatine becoming greenish blue or 



