4o8 



MICRO-ORGANISMS AND DISEASE [chap. 



several spirilla tenua is very distinct in some, though not in 

 others. 



(d) Spirillum iindiila is much thicker and shorter than 

 the former ; there are all forms between such as are only 

 half a turn to such as are of a whole turn of a spiral. It is 

 motile and forms chains of two or more elements, occurring 



f ■/'■ 



'"3 



l\. 



Fig. i66 — .Spirillum Undula. 

 (.^FIER Cuhn). 



Fig. 167. — Spirili.u:\i Volu'ians 

 (after Cohn). 



also in continuous mas.ses, occasionally held together by a 

 hyaline interstitial substance. 



(f) Spirillum volutans. — i:\\Q%it organisms are giant 

 spirilla; long and thick, with granular protoplasm; 25 to 

 30 fj. long ; motile, and with a llagellum at each end. 



(/) Spirillum rosacaim. — I ha^'e seen on paste a spirillum, 

 morphologically identical with spirillum undula ; it is of a 



