590 BACTERIOLOGY. 
under the microscope are seen to be finely granular and 
yellowish or yellowish-brown in color; the colonies are 
round with more sharply defined border, less coarsely 
granular and darker in color than those of the comma 
bacillus. Liquefaction of the gelatin around these col- 
onies progresses rapidly, and at the end of forty-eight 
hours is usually complete in plates where they are numer- 
ous. The surface colonies sink quickly into the gelatiu 
Fie. 80. 
Spirillum of Finkler and Prior. 1100 diameters. 
and present a darker peripheral zone. The differenti- 
ation between the Finkler and Prior and cholera spirilla 
can readily be made in the earlier stages of their growth. 
Later on, and especially when the cholera colonies are 
the older, the diagnosis is not so easy. In gelatin stick 
cultures liquefaction progresses much more rapidly than 
in similar cultures of the cholera spirillum, and a stock- 
ing-shaped pouch of liquefied gelatin is already seen 
after forty-eight hours, which is filled with a cloudy 
liquid. There is no bubble formation. The liquefac- 
