SMALLPOX, SYPHILIS, CANCER, ETC. 179 



In 1905 Siegel described flagellates, which attained their 

 maximum number in the second and third weeks of syphilis. 

 His drawings show round and bluntly crescentic bodies 

 about 2fji with a single flagellum ; the latter was difficult to 

 discern in fresh preparations. Similar bodies were found in 

 thin (2 p.) sections of chancres, where the larger bodies were 

 seen inside, the smaller between the connective-tissue cells. 

 In rabbits and guinea-pigs inoculated with syphilis the same 

 bodies were found in the blood and tissues. 



Later in the same year Schaudinn in the course of an 

 investigation of Siegel' s observations discovered the mobile 

 form, which he named Spirochaeta pallida. His view, 

 stated in Part II, that this was an organism homologous 

 with Leucocytozoon ziemanni, a blood-parasite of owls, has 

 proved to have been formed too hastily. 



Spirochaetes. In 1838 Ehrenberg discriminated between 

 the genus Spirochaeta with flexible bodies and the genus 

 Spirillum with rigid bodies. The best-known spirochaetes, 

 e.g. S. balbianii of the oyster's alimentary tract, have blunt 

 ends and an undulating membrane : 8. pallida on the 

 contrary has taper flagellum-like ends and no membrane ; 

 hence Schaudinn altered the name to Spironema pallida. 

 This later name will be used here as it was in Part II. 



In 1911 Noguchi obtained anaerobic cultures of the 

 spironema in broth containing fresh kidney. Later the 

 medium was changed to white of egg in ascitic fluid broth 

 under paraffin. In some cultures the organisms are thicker 



