214 CLASSIFICATION OF THE MICRO-ORGANISMS. 



of tliis organism which have been furnished by Pasteur 

 van Tieghem, Musculus, v. Jaksch, and others, we learn that 

 the alkaline reaction which occurs in no way interferes with 

 the development of the organism. The fermentation con- 

 tinues till about 13 per cent, of carbonate of ammonia has 

 been formed. Artificially prepared solutions of urea, to 

 which the necessary salts have been added, are rapidly 

 decomposed in the same manner. According to v. Jaksch 

 the best artificial cultivating fluid consists of 3 grammes of 

 urea, 5 grms. of tartrate of potash and soda, O12 grms. of 

 monophosphate of potash, O06 grms. of magnesium sulphate, 

 dissolved in 1,000 ccm. of water. The best temperature for 

 development lies between 30 and 33 C. Musculus has 

 attempted to show that the ferment of the ammoniacal fer- 

 mentation can be separated from the micrococci which pro- 

 duce it, just as the inverting ferment can be separated from 

 the yeast. By precipitation of urine containing much mucus 

 from cases of catarrh of the bladder by means of absolute 

 alcohol, and subsequently drying and pulverising the pre- 

 cipitate, Musculus obtained a substance soluble in water 

 which converts urea very energetically into carbonate of 

 ammonia. Leube was able, nevertheless, to show that pure 

 cultivations of Microc. ureee filtered through plaster cells are 

 inactive, that thus the ferment whidh was isolated is not 

 produced by the organisms, but has perhaps some other 

 source of origin. 



According to v. Jaksch and Billet the micrococcus shows 

 a great variety of vegetative forms in that it can also give 

 rise to rod-shaped forms, which again become changed into 

 chains of cocci. These observations were made on cultiva- 

 tions in which there was no guarantee for their purity, and 

 could not be confirmed either by Leube or in the author's 

 laboratory. 



Leuconostoc mcsenterioides. 



Recognised by Cienkowski and van Tieghein as the 

 cause of the so-called frog-spawn fermentation (Froscli- 

 laichgahrung) of the beet juice and molasses in sugar 

 factories. Forms chains of cocci, which are surrounded 

 by a thick tenacious gelatinous envelope ; large compact 

 gelatinous masses ultimately arise by union of numerous 

 chains. When the nutritive materials are becoming 

 exhausted, the majority of the cells die ; some however, 

 which appear to be larger, with thicker walls and more 



