DESCRIPTION OF SPECIES. 



531 



to the bottom of the liquefied 

 area. 



On agar a smooth slightly 

 brownish layer is formed, and on 

 potato it is yellowish. 



They occur in water. 



Bacillus ramosus (Eisenberg). 

 Rods singly, and in chains ; fila- 

 ments. Spore -formation present. 



Colonies are composed of curi- 

 ously twisted filaments. 



The bacilli inoculated in the depth 

 of gelatine produce delicate fila- 

 ments extending in all directions 

 from the track of the needle, fol- 

 lowed by liquefaction ; later a skin 

 forms on the surface. There is a 

 sediment at the bottom of the tube. 



On agar they form a greyish 

 filamentous layer, and on potato 

 a whitish growth. 



They occur in earth and water. 



Bacillus reticularis (Jordan). 

 Rods 5 p, in length. 1 /x in width ; 

 singly, and in short chains. Motile. 



Colonies are composed of radi- 

 ating filaments, and liquefy the 

 gelatine, forming an excavation with 

 a reticulated lining. 



The bacilli inoculated in the 

 depth of gelatine produce filaments 

 extending from the track of the 

 needle, and at the upper part the 

 jelly is excavated in the form of 

 a cup. On agar they form a dry 

 layer, and on potato a white woolly 

 growth. 



Broth is made turbid, and milk 

 slowly coagulated. 



They occur in water. 



Bacillus rosaceus metalloides 

 ( Bacterium rosaceum metalloides, 

 Dowdeswell ; Magenta bacillus). 

 Rods -6 to -8 \i in breadth. 



Colonies in the depth of gelatine 

 are colourless, but superficial ones 

 are prominent and magenta in 

 colour. 



On the surface of obliquely solidi- 

 fied gelatine they form a beautiful 

 magenta band with a metallic 

 lustre. The gelatine is not lique- 

 fied. Similar growths are obtained 

 on agar and potato. 



It is one of the most striking 

 of all the chromogenic bacteria. 

 Cultures have the appearance of 



having been stained with an alco- 

 holic solution of fuchsine. The 

 colour varies in subcultures from 

 magenta to a sealing-wax-red. 



Bacillus rubefaciens (Zirnmer- 

 mann). Rods '75 to 1/65 \L in 

 length, ~3'2 p. in width, singly, in 

 pairs, and in chains. 



Colonies are faintly reddish- 

 yellow. 



The bacilli inoculated in the 

 depth of gelatine grow along the 

 track of the needle and form a 

 greyish layer on the surface : later 

 the jelly acquires a reddish tint. 



On agar the growth is grey and 

 abundant. 



On potato the growth is at first 

 grey, later reddish-brown, and the 

 surface of the potato has a pink 

 discoloration. 



They occur in water. 



Bacillus rubellus (Okada). 

 Rods resembling those of malignant 

 oedema. They occur singly, in 

 pairs, and filaments ; are motile, 

 and possess flagella, and are often 

 capsulated. They are anaerobic. 



Colonies are whitish, with off- 

 shoots in the surrounding gelatine, 

 which, later, is liquefied, and has a 

 reddish tinge. 



The bacilli inoculated in the 

 depth of gelatine produce a growth 

 in the lower part of the needle 

 track composed of isolated colonies 

 with radiating processes. The jelly 

 is liquefied, at first in the part 

 corresponding with the growth, and 

 later completely. The liquefied 

 gelatine is coloured red. 



In agar the growth extends from 

 below upwards, and the jelly is 

 coloured red. 



In broth they grow rapidly. 



They were isolated from dust. 



Bacillus ruber (Breunig, Bacille 

 rouye de Kiel. Laurent). Rods 

 2*5 to 5 p. long, and ? to "8/n broad. 

 Slightly motile. 



Colonies below the surface of 

 gelatine are pale yellow, and super- 

 ficial ones are blood -red. 



Inoculated in the depth of gela- 

 tine they liquefy it and colour it 

 bright red. There is also forma- 

 tion of gas bubbles. 



