BACILLUS MESENTEE.ICUS VULGATUS 341. 



Bacillus Mesentericus Vulgatus (' Potato Bacillus '). — This 

 organism is found on potatoes and other vegetables, in 

 water, milk, etc. It occurs in the form of short, thick 

 bacilli, often occurring in threads. It is very motile, and 

 forms large oval resistant spores, which fill the interior of 

 the organism. Cultural characters : 



Gelatine Plates. — Small circular yellowish colonies are 

 produced, which rapidly liquefy the gelatine. 



Gelatine Tubes. — In the depth the growth rapidly lique- 

 fies the gelatine along the inoculation track in the form of 

 a funnel ; when the whole contents of the tube have become 

 liquid, a pellicle forms on the surface. 



Agar-Agar. — A dirty-white expansion is formed. 



Potatoes. — Grows rapidly. At first a moist expansion is 

 formed, which afterwards becomes wrinkled and tough. 



Bacillus of Mouse Septicsemia. — This organism was ob- 

 tained originally in garden earth and from putrefying liquids. 

 The organism is exceedingly small, being only about 1 fi in 

 length and from 0"1 to 0*2 fj, in thickness ; it is non-motile. 

 Two organisms frequently occur together, and they contain 

 spores. Mice inoculated die in from forty to sixty hours, 

 when the bacilli are found in the blood, particularly in the 

 capillaries of the kidneys and spleen. Probably identical 

 with hog-erysipelas. Cultural characters : 



Gelatine Plates. — Grows in the depth as a delicate white 

 cloud. 



Gelatine Tubes. — Along the track of the needle in the 

 depth is seen a branching, cloud-like growth, which is 

 more marked in the lower than in the upper layers. No 

 liquefaction of the gelatine takes place. 



Agar-Agar. — Pale yellow sharply-defined colonies are 

 formed. 



Peat Bacteria. — Two organisms, ' ' and ' Q,' have been 



