138 MICRO-ORGANISMS AND FERMENTATION. 



deserving of notice that in the author's laboratory it has 

 been proved that a genuine Saccharomyces (S. fragilis) occurs 

 in Russian kephir-grains which ferments milk-sugar independ- 

 ently, whereas all previous investigators only found budding 

 fungi incapable of spore-formation. 



In some parts of North America a ferment resembling 

 kephir-grains is used in the fermentation of saccharine liquids. 

 According to Mix' researches it contains a yeast-species which 

 coincides with the one described by Beijerinck, and also a 

 Bacterium which resembles Kern's Dispora. 



If one of the kephir-grains is allowed to remain in milk, it 

 grows very slowly, and only attains to double its size, according 

 to de Bary, after the lapse of several weeks. He considers 

 it probable that under such conditions single Dispora cells 

 separate and give rise to new kephir-grains. 



According to A. Levy's published process, kephir can 

 also be obtained without the addition of Kern's ferments. 

 When milk, which is turning sour, is repeatedly and violently 

 shaken, an effervescent alcoholic kephir-like drink is obtained, 

 which does not perceptibly differ from kephir prepared with 

 kephir-grains as regards taste. 



Koumiss is- a similar fermented milk, prepared chiefly 

 from mare's milk by the nomadic tribes of Southern Russia 

 and Siberia ; it has been applied in many countries as a cure 

 for various diseases. The true Koumiss, as prepared by the 

 nomads, is fermented in leathern bottles, fermentation being 

 started by adding a little dried milk from a previous ferment- 

 ation. The organisms present sour and coagulate the milk 

 during their development, and an alcoholic fermentation sets 

 in, with evolution of gas. The coagulated mass is so finely 

 divided that the liquid only turns thick. An accurate exami- 

 nation of the active organisms was undertaken by Schipin, 

 who proved the constant presence of a yeast species, a lactic 

 acid bacterium, and a special species of bacteria which occurred 

 in large quantities, and appears to be characteristic of the 

 Koumiss fermentation. It is a facultative anaerobe which 

 forms whitish colonies in gelatine, consisting of a central 

 nucleus with streamers in all directions. It thrives best 

 on sour-milk gelatine, and does not liquefy the gelatine. By 



