250 BACTERIOLOGY. 



man,* but inoculations of mice, rabbits, sheep, and 

 pigs gave negative results. 



The spirilla were found in the blood of the in- 

 oculated monkeys in great numbers, and also in the 

 brain, lung, liver, kidney, spleen, and skin ; and 

 are believed to be the cause of the disease. 



METHODS OF STAINING THE SPIRILLUM OBERMEIERI. 



In cover-glass preparations of blood the spirilla stain 

 strongly with fuchsine, methyl-violet, gentian-violet, or 

 bismarck-brown. 



In sections, brown aniline stains have been recommended. 



Spirillum cholerse Asiaticae (Comma-bacillus, 

 Koch). Curved rods, spirilla, and threads (Plate I., 

 Fig. 1 8). The curved rods or commas are about 

 half the length of a tubercle-bacillus. They occur 

 isolated, or attached to each other forming S-shaped 

 organisms or longer screw-forms ; the latter resem- 

 bling the spirilla of relapsing fever. Finally they 

 may develop into spirilliform threads. In old cul- 

 tivations threads are found with bulgings or irregu- 

 larities, which are called involution-forms (Plate I., 

 Fig. 35). f The commas are actively motile ; their 

 movements and development into spirilla may 

 be studied in drop-cultivations (Fig. 84). In plate- 

 cultivations, at a temperature of from 16 20 C., 

 the colonies develop as little specks (Fig. 85), which 



* Carter, Lancet. 1879 and 1880. Koch, Cohn 1 s Beitrdge. 

 t Compare also Van Ermengem, Recherches sur le Microbe du 

 Choi. Asiat. 1885. 



