u6 MICRO-ORGANISMS AND DISEASE. [CHAP. 



Caucascus, and which is used as ferment to produce from 

 cow's milk a peculiar drink called "kephir" or "hyppO." 

 The bacillus is similar to the bacillus subtilis, but is dis- 

 tinguished from it and all other bacilli by this, that every 

 bacillus forms two spores, one at each end, hence the name 

 dispora. But after recent investigations it appears that this 

 bacillus is accidental, the fermentation being produced by 

 saccharomyces mycoderma (see Chapter XIV.) 



FIG. 52. BACILLUS SYNCYANUS (AFTER NEELSEN). 



1. Typical bacilli, motile. 



2. Non-motile rods invested in a gelatinous capsule. 



3 and 4. Bacilli in which spore-formation is going on. 

 5. Torula-form of the bacillus. 



Pigment bacilli. 



(a) Bacillus ruber. 1 This appears as minute rods, iso- 

 lated or in twos and fours, and motile. It was found on 

 boiled rice by Frank. Its colour is red, and contained in 

 the bacilli themselves. 



(b) Bacillus erythrosporus. Motile isolated rods and 

 leptothrix. It was found in meat-extract solutions and on 



1 Cohn, Frank, Beitr. z. BioL d. Pflanzen, vol. iii. p. 181. 



