550 



DESCRIPTION OF SPECIES. 



of this process a chain of cocci 

 results, encased in a cylindrical 

 or ellipsoidal envelope. The chains 

 increase in length, become twisted 

 up, and eventually fall apart into 

 pieces of various lengths. 



In nourishing liquids a great 

 number of little masses are formed, 

 which adhere together, and produce 

 pseudo-parenohymatous structures. 

 These latier may join together, 

 forming still larger agglomerations. 



This micro-organism occurs occa- 

 sionally in beet-root juice and the 

 molasses of sugar-makers, forming 

 large gelatinous masses resembling 

 frog-spawn. The vegetation is so 

 rapid that forty-nine hectolitres of 

 molasses, containing 10 per cent, 

 of sugar, were converted within 

 twelve hours into a gelatinous 

 mass ; consequently, it is a for- 

 midable enemy of the sugar manu- 

 facturers. 



Fig. 219. — Leuconostoo mesenteroides. 

 1. Spores. 2. Spores after germination, showing gelatinous envelope. 3, 4, 5, 6. 

 Increase by division. 7. Glomerular form of zoogloea. 8. Section of an old 

 mass of zoogloea. 9. Cocci chains with arthrospores (Tieghem and Cien- 

 kowski). 



The masses of zoogloea are of 

 almost a cartilaginous consistency, 

 and admit of sections being made 

 with a razor. After a long time 

 the envelope liquefies, and the cocci 

 are set free ; the latter introduced 

 into fresh nourishing media develop 

 new colonies. In the chains some 

 of the cocci become enlarged with- 

 out changing their' form. These 

 acquire the properties of spores, 

 and are arthrospores. 



Micrococcus acidi lactici 



(Marpmann). — Large cocci, singly 

 and in pairs. 



Colonies yellowish-white. 



On the surface of gelatine the 

 cocci produce a yellow layer. 



They grow in milk, producing a 

 reddish colour, and coagulation due 

 to the formation of lactic acid. 



They were isolated from milk. 



Micrococcus acidi lactici lique- 

 faciens (Kreuger). — Cocci oval, 1 



