ASIATIC THOLERA. 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 curveil or 

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

 this dise; or. 



, 



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

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



Spirillum cholerse Asiatic (Comma-bacittw, 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'skiP 6 ^ organisms or longer 

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



FIG. 140. ARTHROSPORES ; () Comma-bacillus breaking up into spheres; (b, r), 

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

 with spheres from an old cultivation; (g) germination of UK- spli.-n-. 



(HUEPJ'K.) 



Finally they may develop into spirilliform threads. In old cult 

 tions threads are found with swellings or irregularities (Fig. 1 

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

 Their movements) and development into spirilla may be stu<li<><l in 

 drop-cultivations. Arthrospore formation has been described by 

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



