ASIATIC CHOLERA. 361 



the pngrims to Egypt, and the proximity of England to Egypt, 

 necessitate the greatest possible precautions to prevent the intro- 

 duction of the disease into this country. 



In 1884 a German Commission was sent out to India, and Koch 

 discovered a micro-organism which he described as a curved or 

 comma-shaped bacillus, and pronounced to be the contagium of 

 this disease. 



^, rr 





Fig. 145. — Cover-glass Prepaeation of a Drop of Meat Infusion, containing 

 a pure-cultivation of comma-bacUli, with (a) spirilliform threads, x 600. (KocH.) 



Spirillum cholerse Asiaticse (Comma-ladllus, Koch). — Curved 

 rods, spirilla, and threads. The curved rods or commas are about 

 half the length of a tubercle-bacillus. They occur isolated, or 

 attached to each other forming S'^liaped organisms or longer 

 screw-forms, the latter resembling the spirilla of relapsing fever. 



Fig. 146. — Arthbospoees ; (a) Comma-bacillus breaking up into spheres; (6, c), 

 formation of spheres in spiral forms ; (d, e), groups of spheres ; (/) spirilla 

 with spheres from an old cultivation; (g) germination of the spheres. 



(HUEPPE.) 



Finally they may develop into spirilliform threads. In old cultiva- 

 tions threads are found with swellings or irregularities (Kg. 148). 

 The commas are actively motile, and possess flageUa (Fig. 147). 

 Their movements] and development into spirilla may be studied in 

 drop-cultivations. Arthrospore formation has been described by 

 Hueppe (Fig. 146). In plate-cultivations, at a temperature of from 



