spirillum. 49 



70. S. Undula (Miiller), Ehrenberg {Abhandl. Berlin. 

 Akad., 1830, p, 38). 

 Vibrio Undula, Miiller. 

 V. prolifer, Ehrenberg. 

 Cells 8-12 fL long, I •1-1-4 /«■ thick (according to Raben- 

 horst); spirals wider than in the foregoing, 4-5 /* high; 

 each cell for the most part embracing only \ or i, seldom 



Fig. 48, — Spirillum Undula, X 3000 (after Dallinger). 



I ^ to 2 or 3 spirals; a flagellum at each end. 

 actively motile, at times also forming a zoogloea. 

 45^, 46^, 48.) 



In bog-water and various infusions. 



Ehrenberg gives for S. tenue a thickness of ^^ 

 of a line, for S. Undula only •^ of a line ; at the 

 same time, he says in the description, " Sp. fibris 

 valde tortuosis brevibus, validioribus. " 



According to Warming, .J. Undula is more variable 

 than was formerly admitted. The spirals are often 

 elongated, so that the cell appears almost straight ; 

 accordingly the height of the spirals varies from 3 to 

 lO'S 11, the diameter amounts to |, or -^j of the height, 

 the thickness of the cells '6-1 -3 /j. 



Var. liiorale. Warming {J.c, Re- 

 sum^, p. 23). 



Very 

 (Figs. 



Fig. ^g.—S^iriilum 

 Undula, var. H- 

 torale, X 66o(after 

 Warming). 



£ 



