SYSTEMATIC AND DESCRIPTIVE. 143 



of cholera nostras, and claimed at first to be 

 identical with the comma-bacillus of Koch. They 

 are now regarded as quite distinct, though, 

 like the Spirillum of Asiatic Cholera, they quite 

 recently have been shown to be also patho- 

 genic.* 



Spirillum plicatile, Ehrenberg (Marsh- Spiro- 

 chcete). Thin threads, 2*25 ^ in breadth, with 

 numerous narrow windings, 1 10 125 /xlong, occur- 

 ring also in spirulinar forms. The threads have 

 primary and secondary windings ; the former are in 

 each example of equal size, but the latter are often 

 irregular ; their ends are cut off bluntly, and they 

 exhibit rapid movement. They occur abundantly 

 in marsh-water in summer, and can be obtained by 

 allowing algae to decompose in water. On culti- 

 vation the threads break up into long rods, short 

 rods, and finally cocci. This change is rendered 

 visible by making cover-glass-preparations, and 

 staining with aniline dyes. 



Spirillum Obermeieri (Spirochcete Obermeieri 

 Cohn : Spirillum of Relapsing Fever). Threads 

 similar to the Spirillum plicatile. In length mostly 

 1 6 40 //,, with screw-curves regular (Plate I., Fig. 

 19). They move very rapidly, and exhibit peculiar 

 wave-like undulations. They have been observed 

 in the blood of patients suffering from relapsing 

 fever,f but never in the secretions. They only occur 



* Finkler and Prior, Ergdnzungshefte zum Ce?itralblatt fur 

 allgemeine Gesundheitspflege, Erster Band, 1885. 

 t Obermeier, Med. Centralbl., 1873. 



