246 BACTERIOLOGY 



the conditions decidedly more favourable for the growth of 

 micro-organisms, which can pass on into the intestinal canal 

 along with the substances which the stomach contains. 



According to Arnold, no micro-organisms are found in 

 the stomach of new-born infants, but on the other hand 

 they can be detected after even twenty-four hours of 

 life. 



Sarcina ventriculi. This sarcina was found by Good sir 

 in the contents of the stomach, and shows cells resembling 

 cubes with rounded angles and edges, and which are arranged 

 in fairly large-sized packets (see fig. 1). On the gelatine 

 plate rounded yellowish colonies appear in from one to two 

 days, which show diplococci and tetrads under the micro- 

 scope, but no packets. The gelatine is not liquefied. The 

 thrust-culture shows a growth along the track of the needle 

 and a prominence upon the surface (nail-culture"). A coating 

 of a yellowish-brown colour, consisting of round islets, ap- 

 pears upon agar. On potato a yellow colour becomes visible 

 round the place of inoculation, followed gradually by a warty 

 deposit, and the inoculated spot itself is chrome-yellow. The 

 envelope surrounding the sarcina when in packet shape 

 distinctly exhibits the cellulose reaction, w 7 hich consists of a 

 red colour under the action of iodine and sulphuric acid. 

 While the form of the micro-organism is altered when it is 

 grown on the ordinary culture media, the packet figure is 

 retained in cultivations on neutralised infusion of hay, and 

 can be obtained for observation partly from the pellicle and 

 partly from the precipitated masses. If inoculation be 

 effected from a gelatine plate into the infusion of hay, the 

 packet form will again be assumed by the cocci, which have 

 been arranged on the gelatine as diplococci and tetrads. The 

 sarcina thrives better upon a hay infusion to w^hich two per 

 cent, of cane sugar or glucose have been added (fig. 91). 

 The Sarcina ventriculi very readily takes up the aniline 



