Bacterium. 25 



33. B. fusiforme, Warming (I.e., p. 30, Resume). 

 Cells fusiform, with very acute ends, 2-5 



/u. long, '5 '8 fi thick, in a spongy layer on the 

 surface of the water. (Fig. 16.) 

 In sea-water. 



34. B. Navicula, Reinke et Berthold 



(" Die Zersetzung der Kartoffel 



durch Pilze," p. 21). 

 Cells fusiform or elliptic, nar- 

 rowed towards both ends, pretty 

 large, partly motile, partly station- 

 ary, with one or more dark spots 

 in the interior, which are coloured 

 blue by iodine. (Fig. 17.) 



3 . Fig. 17. Bacterium Navicula, X 



In rotting potatoes. 94 o (after Reinke and Berthold). 



B. CHROMOGENOUS SPECIES. 



35. B. synxanthum (Ehrenberg), Schroter, in Cohn 



(I.e., p. 120). 



Vibrio synxanthus, Ehrenberg. 

 V. xanthogenus, Fuchs. 



Morphologically not different from B. Termo ; "ji i*- 

 long, moving actively, single or united in chains up to five 

 in number. 



Causing the so-called "yellow milk." 



Milk, which has been boiled, and some time afterwards coagulated, 

 often suddenly assumes a lemon-yellow colour, while the caseine by 

 degrees nearly disappears. The milk, originally neutral, becomes first 

 acid, and then intensely alkaline. The filtered lemon-yellow fluid 

 becomes amber-coloured on evaporation ; the resulting yellow-brown 

 crust is not soluble in alcohol or ether, but completely so in water. 

 Alkalies do not affect the colour, which is instantly changed by acids. 



