Spirillum. 47 



67. S. Rugula (Miiller). 



Vibrio Rugula, Miiller (" Infus.," p. 44). 

 Melanella flexuosa, Bory. 



Cells 6-1 6 /A long, about 

 5-2-5 /* thick, either only 

 simply arcuate, or with one 

 shallow spiral, bearing a 

 flagellum at each end, actively 

 rotating round its longitu- 

 dinal axis; the cells are 

 often felted in dense swarms. 

 Height of the spiral generally 

 6-10 p., diameter -5-2 p. Fig . 45 ._ a> spirillum Rugula -, i, s. 



always at the end Of Undula. (a, after Cohn ; b, afte 



Koch's photographs). 



the cell, globose. (Fig. 45^.) 



In bog-water, and various infusions ; also in the slime 

 of the teeth, etc. 



According to Warming, individuals occur the spiral of which reaches 

 a height of 13-20 p. and a diameter of 2-5-5 p. Plasma granular. 



68. S. serpens (Miiller). 



Vibrio serpens, Miiller (" Infus.," p. 44). 



Cells half as broad as in the foregoing species, 11-28 

 p. long (according to Rabenhorst), 'S-i'i p. thick, with 

 several, usually three or four, spirals ; often united in long 

 chains; with a flagellum at each end. Also frequently 

 forming swarms. Height of the spirals 8-12 p., diameter 

 1-2-3 /* (Fig- 46 a, b.} 



In various infusions. 



The dimensions recorded by Rabenhorst (23-28 /u long) presumably 

 refer to threads composed of several cells. According to Warming, the 

 spirals is sometimes as much as 22 p.. 



