BACILLUS ME8ENTEBICU8. 327 



of liquefaction the transparent peripheral zone becomes 

 delicately granular, at the periphery appears a row of 

 fine hairs, and the entire colony assumes the character of 

 a liquefying subtilis colony. The center is usually gray- 

 ish-brown and opaque (43, ix). Deep: Grayish-yellow, 

 irregular; about the edge are curling, hairy outgrowths. 



Gelatin Stab. — The colony after twelve to twenty-four 

 hours sinks into a saucer-shaped depression. The liquefac- 

 tion first assumes a funnel form and later progresses in a 

 cylindric manner. The contents of the funnel are cloudy, 

 with a whitish-gray film upon the surface (43, i). 



Agar Plate. — 



(a) Natural size: Roundish, gray, thin, veil-like 

 growths, transparent, with the original whiter colony in 

 the center (43, v). 



(6) Magnified fifty times : The original colony lying be- 

 neath the superficial colony appears yellowish-brown, 

 moderately or very crummy, with an even border or with 

 curling outgrowth. When the colony reaches the surface, 

 it forms a delicately punctated, transparent, irregular 

 growth of a gray to yellowish color (43, vii). 



Agar Streak. — Wavy, moistly shining, yellowish- 

 brown, in many places gray and transparent. Water of 

 condensation cloudy, with yellowish precipitate and a 

 pellicle upon the surface (43, ii). 



Bouillon. — ^Moderately cloudy, pellicle on the surface. 



Potato. — At first the growth is moderately elevated, 

 grayish-yellow, moistly shining, slimy (43, in). Later it 

 is transformed into a meshwork of irregularly anasto- 

 mosing wrinkles, which are much elevated, of a yellow- 

 ish-gray color, and possess a dull luster (43, iv). 



Chemical Activities. — See preliminary- remarks on 

 page 306. It forms little indol and abundant HjS. 



Distribution, Practical Importance, Etc. — Like Bac. 

 vulgatus. 



Bacillus mesentericus ruber. Globig (Z. H. iii, 322). 



Slender bacilli, 1 to 3.2 ^u long, 0.4 /i thick, sometimes forming quite 

 long threads. Not motile, stain by Gram's method, no spores. The 

 gelatin plate exhibits quite variable forms. At iirst all the colonies 

 present an appearance like typhoid; later some colonies retain the 



