HARDWICKE'S SCIENCE-GOSSIP. 



85 



Spirillum, because gross misuse has been made of the former, 

 especially by non-botanists, so that it is better to let it lapse 

 altogether. 



58. S. Rugida (Miiller). 



Vibrio Rugula, Miiller. 

 Melanella flexuosa, Bory. 

 Cells 6-16 \l long, about £-2§ ^ thick, either only 

 simply arcuate, or with one shallow spiral, bearing a 

 flagellum at each end, actively rotating round its 

 longitudinal axis ; the cells are often felted in dense 

 swarms. Height of the spiral generally 6-10 ft, 



Also frequently forming swarms, 

 spirals 8-12 n, diameter 1 '2-3 ju. 

 In various infusions. 



Height of the 



The dimensions recorded by Rabenhorst (13-28 /j. long) pre- 

 sumably refer to threads composed of several cells. According 

 to Warming, the height of the spirals is said to be sometimes as 

 much as 22 /j.. 



60. S. tentce, Ehbg. 



Cells very slender, 4-15 m long, about 2\ /x thick 

 (according to Ehrenberg), with at least ih, usually, 

 however, 2, 3, 4 or 5 spirals. Height and diameter 

 of the spirals about I j-4 /u, or the diameter amounts 



Fig. 66.— Spirillum Jenense (after Ehr.) X 600. 



Fig. 65. — a, Spirillum serpens ; i, the same, felted in a " swarm ' 

 c, S. tenue ; d, S. undula; e, S. volitions (after Cohn), X.650. 



Fig. 67. — Spirillum sanguineum 

 (after Koch), X 600. 



Fig. 68.— Spirillum undula (after Dallinger). 



diameter '5-2 /a. Spores always at the end of the 

 cell, globose. 



In bog-water, and various infusions j also in the 

 slime of the teeth, &c. 



According to Warming, individuals occur the spiral of which 

 reaches a height of 13-20 /x and a diameter of 2*5-5 f- 



59. S. serpens (Miiller). 



Vibrio serpens, Miiller. 



Cells half as broad as in the foregoing species, II- 

 28 n long (according to Rabenhorst), "8-1 ' 1 fi thick, 

 with several, usually three or four spirals ; often 

 united in long chains ; with a flagellum at each end. 



to half the height. Moving very swiftly, but also 

 often almost motionless and felted in dense swarms 

 or masses, or united in a zooglcea. 

 In various infusions. 



According to Warming only 1 ft thick, and the spirals 

 times 8-10 /x high, with the diameter \-& of the height. Th 

 appears to be some confusion between i". tenue and S. Undi 



Is at 

 times 8-10 /x High, witn tne aiameter j~*% 01 tne neight. There 

 appears to be some confusion between i". tenue and S. Undula. 



61. S. Undula (Miiller), Ehbg. 



Vibrio Undula, Miiller. 



V. prolifer, Ehbg. (Infus. p. 81, pi. v., 

 fig. 8.) 

 Cells 8-12 m long, n-l-4/i thick (according to 



