616 THE GUM FERMENTATION OF SUGAR CANE JUICE, 



processes are clouded and finely granular, with a clear central 

 canal. Group /3/3 : the colonies vary from dirty white to buff- 

 white, and have a fatty or dull appearance. When magnified, 

 the deep colonies are seen as irregular clumps ; the surface 

 colonies appear dark grey and marbled, with either a stippled or 

 a filamentous margin, and a smooth or a rough edge. 



^'accharose{lO %)-7^6p^^^'?(iV %)-^^^^' P^^'^^- — The colonies of 

 the a and /3 types appear like raised drops of whey upon an 

 amoeboid base. When magnified, the deep colonies are lenticular 

 and clouded ; the surface colonies being clouded and hatched. 

 The amoeboid processes of the surface colonies have a hatched 

 centre, a finely granular intermediate portion, and a clear margin. 

 The colonies of the /3^ type are circular and yellowish, or dirty 

 white. The agar below the surface may swell into a dome-shaped 

 prominence bearing the colony. Subsurface colonies cause the 

 agar to swell locally and split. 



Agar stroke. — Group a : The races form a translucent white 

 amoeboid growth spreading over the greater portion of the agar 

 surface. The growth becomes irregularly furrowed or indented, 

 and appears either dry or slightly moist. Sometimes the surface 

 is covered with minute drops of fluid, which gives the culture a 

 shagreen appearance. The upper margin of the stroke is fre- 

 quently raised and glistening. The central portions adhere so 

 firmly to the agar that it is impossible to remove portions with 

 the ordinary thin platinum needle. The condensed w^ater is 

 covered with a strong, white, wrinkled film. Group j3 : The 

 cultures are whiter than the a races, and show a greater diversity 

 of appearance. The growths are amoeboid, and either flat or 

 terraced, They may be dry or glistening. A white central 

 portion ma}^ have a narrow or broad raised translucent margin. 

 Some races differ from those of the a group only in having a fatty 

 consistence, so that portions of the culture can be easily removed 

 with the needle. Like the a group, the cultures form a strong, 

 white, wrinkled film on the condensed water. Group /3/3 : The 

 o-rowth is broad, raised, luxuriant, and varies in colour from 

 primrose through stone to buff. It is lobular and spreading, but 



