ASIATIC CHOLERA. 361 



the pilgrims 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. 





FIG. 145. COVER-GLASS PREPARATION OF A DROP OF MEAT INFUSION, containing 

 a pure-cultivation of comma-bacilli, with (a) spirilliform threads, x 600. (Kocn.) 



Spirillum choleras Asiatics (Comma-bacillus, 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~ sna P ec l organisms or longer 

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



FIG. 146. ARTHROSPORES ; () Comma-bacillus breaking up into spheres; (b, c), 

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

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



(HUEPPE.) 



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

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

 The commas are actively motile, and possess flagella (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 



