NON-PATHOGENIC SPIRILLA. 697 



418. SPIRILLUM UNDULA (Ehrenberg). 



Found in putrefying animal and vegetable infusions. 



Morphology. Rigid, spiral filaments, from 8 to 12 /* long and from 1.1 

 to 1.4 H thick. Each spiral turn has a length of 4 to 5 jn and each filament 

 from one-half to three turns. A long, whip-like flagellum may be demon- 

 strated at each extremity. The movements are rotary and rapidly progres- 

 sive darting. 



Biological Characters riot determined. 



419. SPIRILLUM TENUE (Ehrenberg). 



Found in putrefying vegetable infusions, etc. 



Morphology. Slender spiral filaments, from 4 to 15 ft long. The height 

 and length of a single turn are from 2 to 3 u, and each filament has from 

 one and a half to five turns. Often associated in closely crowded swarms. 

 Motions rotary and progressive extremely rapid. 



Biological Characters not determined. 



420. SPIRILLUM LINGU/E. 



Synonyms. Vibrio lingualis; Zungenbelag vibrio (Weibel). 



Obtained from deposit upon the tongue, by inoculation in a mouse. 



Morphology. Curved rods of the size of the cholera spirillum ; sometimes 

 in S- shape. Grow out into longer or shorter wavy filaments, the 'extremi- 

 ties of which are sometimes enlarged button-like. Involution forms are 

 common. 



Stains by Gram's method, and is differentiated by this from other 

 ' ' vibrios " described by Weibel. 



Biological Characters. An aerobic and facultative anaerobic, non. 

 liquefying, non-motile spirillum ("vibrio"). 

 Spore formation not determined. Grows 

 at the room temperature in the usual cul- 

 ture media. Upon gelatin plates forms 

 dirty -white colonies, which at the end of a 

 week may attain a diameter of one milli- 

 metre. Under a low power the margin of 

 the deep colonies is seen to consist of fine, 

 white, interlaced filaments, with irregular 

 offshoots. The margin of the superficial 

 colonies has a greenish-yellow shimmer, 

 and thread-like offshoots are given off in 

 a tangential direction ; the contour is round. 



In gelatin stick cultures a delicate, white, Fm. 250. Spirillum linguae. (Weibel.) 

 veil-like stripe is developed along the line 



of puncture, and no growth occurs upon the surface. Upon the surface of 

 agar a dirty-white, finely granular not slimy layer is developed. In 

 bouillon a flocculent deposit collects at the bottom of the tube, and the liquid 

 above is slightly clouded. The flocculi in bouillon cultures consist of closely 

 interlaced filaments, and frequently shorter rods or fragments are so placed 

 as to give the impression that they are bud-like offshoots from the longer 

 filaments. 



Not pathogenic for Avhite mice. 



421. SPIRILLUM NASALE. 



Synonyms. Vibrio nasalis; Naseiischleimvibrio (Weibel). 



Found in nasal mucus. 



Morphology. Curved rods with rounded ends, about as thick as the an- 



