CHAPTER I 



BACTERIOLYSIS 



Bacteriolysis. Technic for Isolating the Bacteriophage. Enhancement 

 of Virulence. Technic for Enumeration. Multiplication at the 

 Expense of the Bacteria in a Fluid Medium. The Bacteriophage; an 

 Obligatory Parasite. Effect of the Condition of the Bacterium. Effect 

 of the Medium. Cultivation on Solid Media; Isolated Colonies. Effect 

 of the Concentration of Bacteria in the Medium. Destructive Action of 

 the Secretory Products of the Bacteriophage. Effect of External 

 Physical Conditions. Effect of Antiseptics. The Soluble Bacterial 

 Substance. The Bacteriophagous Ultramicrobe ; an Internal Parasite. 

 Bacteriolysis under the Microscope. 



BACTERIOLYSIS 



It is expedient to define, at the beginning of this work, what 

 is meant by the word "bacteriolysis" for it is a scientific term 

 used in a somewhat equivocal manner. 



The term "autolysis" was introduced into science byJacoby 

 as a substitute for the word "autophagy" which had previously 

 been employed to designate the process of softening; the tendency 

 toward a liquefaction, more or less marked, such as is produced 

 by a yeast isolated upon a nutrient medium. The term autophagy, 

 which presumed nothing as to the final condition of the process, 

 is more suitable certainly, than that of autolysis. Etymologi- 

 cally the latter signifies auto-dissolution, whereas as a matter of 

 fact, the process of autolysis, as it occurs with bacteria and yeasts 

 even if prolonged for several months, never results in a complete 

 cellular dissolution. The end product is a semifluid mass, which, 

 examined microscopically, shows cellular debris along with a 

 greater or less number of cells more or less profoundly modified. 

 The degree of disintegration depends somewhat upon the type : 

 of bacterial cells employed. Autolysis, then, is characterized, 

 not by an actual dissolution, but by a disintegration, a cellular 

 fragmentation with a partial dissolution of certain elements. 

 Even in the most favorable cases, when the autolysis is considered 



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