ABOUT CHOLERA 



241 



de-oxygenation of the fluids 

 and organic substances in which 

 they can, when exactly suited, 

 multiply with tremendous ra- 

 pidity. Thus the tubercle 

 bacillus cannot be cultivated on 

 pure blood-serum, but if a trace 

 of glycerine be added to the 

 serum the tubercle bacillus 

 grows, divides, multiplies like 

 yeast in a brewing -vat. A 

 little later Pettenkofer's auda- 

 cious experiment was repeated 

 by Dr. Metchnikoff in Paris. 

 He swallowed a cultivated mass 

 of the cholera germ on three 

 successive days, and had no 

 injurious result. Others in his 

 laboratory did the same, with 

 the result of only a slight in- 

 testinal disturbance. But of a 

 dozen who thus put the matter 

 to the proof in the Institut 

 Pasteur, one individual acquired 

 an attack of true Indian cholera, 

 accompanied by all the most 

 violent symptoms, which very 

 nearly caused his death. This 

 experiment put an end to all 

 discussion, and demonstrated, 

 once for all, that the comma- 

 bacillus (or spirillum) of Koch 

 is really capable of producing 

 Indian cholera, and is the actual 

 agent of this disease. 

 16 



FIG. 46. a, 6, c, d. The cholera 

 spirillum, or comma-bacillus of 

 Koch ; a, spirillum stage of 

 growth, with vibrating flagel- 

 lum, by which it is driven along 

 with screw-like movement ; b, 

 the spirillum has lost its flagel- 

 lum, and is motionless : it is 

 marked off into separate seg- 

 ments ; c, the segments have 

 separated from one another as 

 comma-shaped pieces, hence 

 the name " comma-bacillus " 

 given to it by Koch; d, a 

 number oi comma-bacilli of 

 cholera which have developed 

 tails of vibratile protoplasm 

 (like a single cilium), and are 

 swimming about, being driven 

 by the lashing of these tails ; 

 e, a cubical packet of sarcina ; 

 y, a double row of the spheri- 

 cal units (cocci or micrococci), 

 which form a sarcina-packet ; 

 g, similar cocci separated. 



