84 MICRO-ORGANISMS AND FERMENTATION. 



will grow very slowly and only attain, according to DE BARY, 

 to double its size 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 the mode of preparation published by A. LEVY, 

 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, as regards taste, etc., does not 

 perceptibly differ from kephir prepared with kephir-grains. 



The Ginger-leer Plant, which presents morphological re- 

 semblances to the Kephir ferment, has been examined from a 

 botanical and biological point of view by Professor MARSHALL 

 WARD. If this ferment is introduced into saccharine solutions 

 to which ginger has been added, it transforms them into an 

 acid effervescing beverage, ginger-beer. When fresh, it occurs 

 as solid, white, translucent lumps, of irregular shape, brittle 

 like dried jelly, their size varying from that of a pin's head to 

 that of a large plum. It induces an alcoholic fermentation in 

 the saccharine solution, which at the same time becomes viscous. 

 MARSHALL WARD isolated the numerous micro-organisms exist- 

 ing in the masses described above, and gave accurate descrip- 

 tions of a series of yeast-fungi, bacteria and moulds, among 

 which two organisms proved to be essentially concerned in the 

 fermentation of ginger-beer. One of these is a Saccharomyces, 

 belonging to the ellipsoid group of this genus, and probably 

 originating from the ginger and brown sugar commonly em- 

 ployed ; the author has named it Saccharomyces pyriformis. 

 It inverts cane-sugar, actively ferments the products, and forms 

 a white pasty deposit at the bottom of the vessel. It yields 

 spores on gypsum blocks at 25 C. in 40 to 50 hours ; it also 

 forms spores on gelatine. In hopped wort it induces a rather 

 feeble fermentation, and forms a film on the surface ; many of 

 the cells in this film are pear or sausage-shaped. 



The other constantly occurring and essential form is a 

 Schizomycete, Bacterium vermiforme, which, according to Pro- 

 fessor WARD, originates from the ginger, and is active in the 

 lactic acid fermentation. It is a peculiarly vermiform organism, 

 enclosed in clear, swollen, gelatinous sheaths, and imprisoning 



