8ABCINA. 151 



summits," and along the stab as luxuriant stalactite-like 

 masses. The colonies are at first cartilaginous, then moist, 

 and finally pap-like. Upon grape-sugar agar plates the 

 superficial colonics are warty and luxuriant and spread 

 like a wrinkled film ; the deep ones are at first smooth and 

 later sago-like warty balls. 



Microscopically the form upon sugar media presents 

 tough, thick, gelatinous capsules (of dextran, compare 

 p. 30). 



The gelatinous covering protects for fifteen minutes 

 against 75°. All the varieties of sugar ordinarily em- 

 ployed undergo fermentation, with the formation of gas 

 and acid. The fungus formerly was often the cause of 

 the very troublesome frog-spawn fermentation of sugar 

 solutions in sugar factories. 



Leuconostoc lagerheimii Ludwig consists of small 

 (0.6 ,u to 0.8 /i) cocci within thick capsules. It causes 

 alcoholic fermentation in the slimy secretion from oaks. 

 The organism is said to occur also without envelopes as 

 short rods with flagella (?). 



2. Sarcina (Goodsir). 



The cells divide (at least upon suitable nutrient media 

 — hay decoction, bouillon) in regular succession in three 

 directions of space, and remain grouped in larger or 

 smaller cubical families. ^ 



The boundary of this genus is not sharp, although 

 the sarcina is held by many authors (Nageli!) as an 

 especially natural genus. Many varieties only produce 

 true cubical arrangement upon certain nutrient media, and 

 it appears that this property may also be acquired or lost 

 (compare Sarc. rosea). In the case of varieties with in- 

 complete packet formation there is always doubt whether 

 they belong to the sarcina ox micrococcus. It is our con- 

 viction that the sarcina is connected with the micrococcus 

 by unbroken transition forms, and is only separated arbi- 

 trarily. Examples follow. 



' We call eight oubioally arranged cocci a packet ; cubical combina- 

 tions of packets, halea of packets ; irregular combiuatious, heaps of 

 packets. 



