138 BACTERIOLOGY. 



twenty-four hours. Liquefaction sets in very 

 slowly, commencing at the top of the needle 

 track around an enclosed bubble of air, and forms 

 a funnel continuous with the lower part of the 

 growth (Plate III., Fig. i) ; the latter preserves 

 for several days its resemblance to a white 

 thread (Figs. 33 and 34).* In about eight days, 

 however, this too is liquefied, with the exception 

 of the deepest part of the needle track, which 

 disappears only at the moment when all the rest 

 of the gelatine is liquefied. 



On a sloping surface of agar-agar the cultivation 

 develops in the form of a white, semi-transparent 

 plaque, with well-defined margin, and the liquid 

 which is found at the bottom of the oblique surface 

 becomes milky. In potato-cultivations the microbe 

 will only grow at the temperature of the blood 

 (37 C.), forming a slightly brown, transparent layer. 

 Inoculation of a cultivation of the bacillus in the 

 duodenum of guinea-pigs, with t and without f 

 ligation of the bile duct, has given positive results. 

 More recently these results have been confirmed 

 by the following method. A 5 per cent, solution 

 of potash was injected into the stomach of guinea- 

 pigs, and twenty minutes after, a cultivation of 

 comma-bacilli diffused in broth was similarly in- 



* Reprinted from Remarks on the Comma-Bacillus of Koch, 

 Lancet, 1885., 



t Nicati et Rietsch, Communication a r Academic de Medecine* 

 1884. 



\ Van Ermengem, Le Microbe du Cholera Asiatique. 1885. 



