SYSTEMATIC DESCRIPTION OF SPECIES. 73 



Sp. buccalis, Sp. dentium, Sp. vincenti, Sp. gracilis. 



Sp. schaudinni. 



Spirochaetes in gangrenous processes, haemoptysis, 



etc. 



Sp. microgyrata. 



Sp. in small-pox and vaccine lymph. 

 Sp. refringens, Sp. balanitidis. 

 Sp. pseudo-pallida. 

 Sp. pallida. 

 Sp. pertenuis. 



Sp. lymphatica and forms found in anaemia. 

 Sp. aboriginalis. 

 Sp. interrogans. 

 Various doubtful spirochaetes and spirilla. 



LARGE SPIROCHAETES. 



SPIROCH^ETA PLICATILIS. 



(Ehrenberg, 1833.) 



This, the first discovered species of spirochsete, is 

 found in stagnant fresh water, especially along with 

 algae of putrefaction. It attains a length of 200^, but 

 its average length is 80/1 and its breadth 0.5;* (Doflein). 1 

 In shape it shows a double series of spiral curves, a 

 larger series producing a generally undulating appear- 

 ance, and a smaller series imposed upon these (Figs, i, 

 58) . Its extremities are rounded, according to Biitschli : 

 but Laptschinsky thinks that they are normally sharp 

 and that blunt ends indicate that the organism has 

 broken into pieces. It is flattened in form, like a ribbon. 

 It possesses a periplastic sheath and contained ento- 

 plasm. Along the central axis is a refringent central 

 rod, which stains darkly; granules of staining sub- 

 stance (nuclei) are arranged along this rod. This spiro- 

 chaete, according to Butschli, has no undulating mem- 



1 Illustrations of the organism make it appear much broader. 



