SYSTEMATIC AND DESCRIPTIVE. 



surrounded by a thick gelatinous envelope (Fig. 

 101). The life-history has been very thoroughly 

 investigated.* The spores, 1*8 2 JJL in diameter, 

 are of a round or ellipsoidal form, with thick mem- 



FIG. 101. LEUCONOSTOC MESENTEROIDES. 



I. 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 arthro- 

 spores [after Tieghem and Cienkowski]. 



brane and shining contents. The outer membrane- 

 layer bursts, and a middle lamella oozes out, and 

 forms a thick gelatinous envelope, while the inner 

 layer remains adherent to the plasma. Thus the 

 spore-germination leads to the formation of a 



* Cienkowski, Die Gallertbildungen d. Zuckerrubensaftes. 1878 ; 

 and Van Tieghem, " Sur la Gomme de ucrerie," Ann. Sc. Nat. 

 1879. 



