478 CHOLERA 



smaller. Its growth in gelatin is also somewhat similar, but liquefaction 

 proceeds more rapidly, and the bell-shaped depression on-tlie surface is 

 larger and shallower, whilst the growth has a more distinctly yellowish 

 tint. The colonies in plates also show points of resemblance, though the 

 youngest colonies are rather smoother and more regular on the surface, 

 and liquefaction occurs more rapidly than in the case of the cholera 



Fici. 142. — Finkler and Prior's spirillum ; from an agar culture 



of twenty-four hours' growth. 



Stained with carbol-fuchsin. x 1000. 



organism. The colonics have, on naked-eye examination, a distinctly 

 yellowish colour. The organism does not give the cholera-red reaction, 

 and on potato it forms a thin yellowish layer when incubated above 

 30° 0. When tested by intraperitoneal injection and by other methods, 

 it is found to possess very feeble, or almost no pathogenic properties. 

 Deneke's spirillum is usually regarded as a comparatively harmless 

 saprophyte. 



