532 



DESCRIPTION OF SPECIES. 



Potato is rapidly covered with a 

 purplish-red growth. Broth be- 

 comes turbid, and pink in colour. 



Milk is coagulated, and a blood- 

 red colour develops on the surface 

 and gradually extends. 



They were found in water. 



Bacillus rubescens (Jordan). — 

 Eods 4 /i in length, -9 ;a in width, 

 singly, in pairs, and short chains. 



Colonies pure-white. 



Inoculated in the depth of gela- 

 tine there is a little growth in the 

 track of the needle, and a pure- 

 _white prominent patch on the free 

 surface. 



On agar the growth is white and 

 shining, and later has a pink tinge. 



On potato the growth is flesh- 

 coloured. 



Broth becomes turbid, and a scum 

 forms on the surface. 



Milk after a time acquires a pink- 

 ish colour. 



They occur in sewage. 



Bacillus rubidus (Eisenberg).— 

 Rods and filaments. 



Colonies circular, granular, and 

 slightly red. 



The bacilli inoculated in the depth 

 of gelatine produce liquefaction and 

 a brownish-red colour. 



On agar and potato they form a 

 brownish-red growth, and liqufefy 

 blood serum. 



They occur in water. 



Bacillus sanguinis typhi 

 (Brannan and Cheeseman). — Rods 

 1 to 2o fi in length, -b to '8 n in 

 width ; singly, in pairs, and in 

 chains, and involution forms. 



Colonies granular, pale-brown. 



The bacilli inoculated in the 

 depth of glycerine-agar produce a 

 growth in the track of the needle 

 composed of isolated, minute, white 

 colonies. 



Rabbits inoculated die in from 

 two weeks to a month. 



They were isolated from the 

 blood of patients suffering from 

 typhus fever. 



Bacillus saprogenes (Rosen- 

 bach). — Three rod-formed organ- 

 isms have been described by 

 Rosenbach as intimately associ- 

 ated with putrefactive processes. 



No. 1.— Large rods (Pig. 210), 

 which form an irregular sinuous 

 streak with a mucilaginous appear- 

 ance when cultivated on nutrient 

 agar-agar. Spore-formation pre- 

 sent. They grow also very readily 

 on blood serum, and all cultivations 

 yield the odour of rotting kitchen 

 refuse. They are not pathogenic. 



No. 2. — Rods shorter and thinner 

 than No. 1. They develop very 

 rapidly on agar-agar, forming trans- 

 parent drops, which become grey. 

 The cultivations yield a character- 

 istic odour similar to the last. 



Fig. 210.- 



-Baoillus saprogenes, No. 1. 

 (Rosenbach. ) 



They are pathogenic in rabbits. 

 They appear to be identical with 

 Bacillus foetidus (Bacterium foeti- 

 dum. Thin). They were isolated 

 from a patient suffering from pro- 

 fusely-sweating feet. 



No. 3. — See Bacterium sapro- 

 genes. 



Bacillus scissus (Frankland). — 

 Very short rods, 1 to 2 /.i in length, 

 and 1 fi in width. 



Colonies yellowish, opaque in the 

 centre, and periphery dentated. 



Inoculated in the depth of gela- 

 tine there is no growth in the 

 track of the needle, but a shining 

 layer forms on the surface, and the 

 jelly is coloured greenish. 



On agar the growth is shining 

 and the jelly coloured green. 

 ' On potato the growth is flesh- 

 coloured. 



They occur in earth. 



Bacillus septicaemise hsemor- 

 rhagicsB (p. 231). 



Bacillus septicus (Klein).— 

 Rods varying in size. Non-motile. 

 They form threads or leptothrix 

 filaments, and are rounded at the 

 ends. They are anaerobic, and form 

 spores independently of access to air. 



