23 8 CLEAN MILK 



Spirillum— cylindroidal bacteria, having- a spiral twist. (Plural, 

 spirilla.) Very often the spiral twist is so slight, that single 

 individuals appear like commas— hence the term comma bacil- 

 lus, which really indicates a short spirillum. When in chains, 

 however, the spiral twist is very evident. 



HIGHER BACTERIA. 



The much elongated or filamentous forms, included in the 

 Migula-Chester classification, as streptothrix and chlamydo-bac- 

 teriacae. (Note. — The " mycobacterium " of this classification is 

 still often regarded and spoken of as " bacillus.") 



Whether bacteria are animal or vegetable in character is not 

 settled — and matters little. They resemble both in many features, 

 and differ from both in many others. At first considered animal, 

 they were later believed to be vegetable, but now it is admitted that 

 their exact position is not clear. 



Essentials of Bacterial life. — All living bacteria exist in one of 

 two conditions, the active growing multiplying condition and the 

 dormant or quiescent condition. The quiescent condition is reached 

 as the result of food exhaustion or poisoning with their own excreta, 

 drying or other unfavorable conditions ; those bacteria which form 

 spores have therefore two quiescent conditions, the spore, and the 

 quiescent condition common to all bacterial cell. The dormant con- 

 dition of the non-spore-bearing bacterial cell, due to self-poisoning; 

 from its excreta, is likely to terminate in the death of the organism 

 and its destruction by its own products (autolysis) if the material in 

 which it lies remains moist: if drying occurs, however, before the 

 death of the cell, it will become dormant but remain alive and re- 

 sistant to outside influences for considerable periods, returning to 

 the active condition if it reaches favorable surroundings; but the 

 quiescent condition of the cell is not so resistant as the spore state. 



