ZOOLOaY AND BOTANY, MICKOSCOPY, ETC. 383 



Bacteria of Caucasian Milk Ferment.* — E. Kern describes a new 

 genus and species of bacteria found in " kephir," a drink prepared by 

 the inhabitants of the high-lying lands in the Caucasus by fermenta- 

 tion of cows' milk. It is also used as a remedy against diiferent 

 diseases. 



As a ferment in its preparation strange white lumps are em- 

 ployed, of a spherical or elliptical shape, in size from 1 m. to 5 cm. 

 Microscopical examination showed that they consisted of yeast-cells 

 and bacteria. The yeast-cells are the ordinary form, produced by 

 cultivation, of Saccharomyces cerevisice, but Kern was unable to get 

 these to the spore-bearing stage. The bacteria composed the chief 

 part of the lumps, and were in the zoogloea state. The vegetative 

 bacteria cells were 3 • 2 m. to 8 m. in length and • 8 broad. In prepa- 

 rations put up by drying, a distinct cell-membrane could be dis- 

 tinguished. 



Treated after Koch's method, the cells show at one end a loco- 

 motive organ, which resembles a cat-o'-nine-tails of threads. When 

 exposed to acids or a high temperature, the cells grow out, 

 probably through progressive cell-divisions, into long Leptoilirix 

 threads, which change generally precedes the spore-formation stage. 

 The spores are round, always formed in twos in each cell, and are 

 always placed standing on their ends ; even by a Hartnack immersion 

 X, no partition-wall could be discovered between the spores. In the 

 Leptothrix-ihvQ&di?, rows of spores could be observed, which are, 

 however, always so situated that two spores belong to each cell. 

 The spores while still in the cells are • 8 /x in size ; those lying free 

 attain the size of 1 /x ; the germinating spores swell up 1-6 //, 

 The germination of the spores generally takes place in such a 

 manner, that an exosporium and an endosporium can always be 

 distinguished in them. The thinner endosporium arises out of the 

 thicker exosporium, first as a small excrescence, which gradually 

 increases, developing more and more into a long cylindrical tube, 

 and then begins by cell-division to form vegetative cells. The 

 whole course of the development to the spore formation, beginning 

 with the vegetative cell to the formation of a similar new cell, was 

 followed. 



This new form of bacteria, which undoubtedly belongs to the 

 Desmobacteria of Cohn, is, in its vegetative state, not unlike Bacillus 

 subiilis ; it is, however, clearly distinguished not only from it, but 

 also from all other kinds of Bacteria by its spore formation, since 

 it always forms in each cell two round spores, placed end to 

 end, while in the species of Bacteria hitherto described, only one 

 spore has been noticed in each cell. On account of this sharply 

 marked feature Kern places this form of Bacteria in a new genus, 

 next to Bacillus, and calls it Dispora caucasia nov. gen. et sp. 



A more exhaustive essay on the subject, witli exjilanatory plates, 

 Kern promises in a forthcoming number of the ' Bulletin de la 

 Societe Imperiale des Naturalistes de Moscou.' 



* Bot. Ztg., xl. (1882; pp. 264-G. Cf. Xatuic, sxvi. (1882) p. 43. 



