104 THE BACTERIA IN ASIATIC CHOLERA. [CH. 



liquefied the gelatine, the aspect and nature of the colonies, 

 the manner in which they grew in gelatine tubes, and the 

 microscopic appearances of fresh specimens and of dried 

 and stained specimens, were similar. The other and 

 slightly larger variety behaved altogether in a different way. 

 This did not liquefy the gelatine, it formed in plate- 

 cultivations single greyish rounded specks (see Fig. 33) 

 which only slowly enlarged, and even after a week or ten 

 days were not larger than a few millimetres in diameter, 

 their outline being irregular, their colour greyish, and their 

 aspect under a lens more or less granular. In gelatine 

 tubes (10 per cent, alkaline gelatine) inoculated by the 

 platinum-wire in the depth stab-culture, there appeared 

 after several (three or four) days the first traces of the 

 growth in the shape of a greyish streak, slowly thickening 

 and broadening, and assuming a more or less granular 

 aspect; on growing it on the surface of 10 per cent, alkaline 

 nutritive gelatine in streak culture, a greyish film appears, 

 gradually expanding in breadth, but even after several weeks 

 it is only a few millimetres in breadth ; in the streak of 

 inoculation the growth is thickest, and assumes after two or 

 three weeks a slight reddish-brown tint, while the rest is 

 greyish and thin. After some months the film is about half 

 an inch broad, thin and grey in the peripheral part, thicker 

 and of a reddish-brown tint in the middle. The outline 

 of the film is smooth in some places, slightly crenate in 

 others. At no time, not even after some months, is there a 

 trace of liquefaction of the gelatine. These comma-bacilli 

 grow well on alkaline Agar-agar mixture, also, but not so 

 copiously, on vegetable albumen and Agar-agar mixture, or 

 egg-albumen and Agar-agar mixture, forming on all these 

 media a greyish film, which as time goes on assumes 

 in its thickest parts a brownish tint. In microscopic 



