1 86 



MICRO-ORGANISMS AND DISEASE. [CHAP. 



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 

 also in continuous masses, occasionally held together by a 

 hyaline interstitial substance. 



/' 



r 



FIG. no. BLOOD OF RELAPSING FEVER (HUMAN). 



Blood-corpuscles and spirilla Obermeyeri. 



Magnifying power 700. (After Koch.) 



(c) Spirillum volutans. These organisms are giant 

 spirilla; long and thick, with granular protoplasm; 0^025 

 to 0*03 mm. long; motile, and with a flagellum at 

 each end. 



2. Pigment spirilla. 



(a) I have seen on paste a spirillum, morphologically 

 identical with spirillum undula; it is of a pale pink 



