190 LIFE OF ELIE METCHNIKOFF 



Syphilography of the same city, completed the capital 

 required to execute the projected plan. 



The following is a short sketch of the researches that 

 were undertaken and the results that were obtained. 



The inoculation of anthropoid apes with syphilis 

 was successful. The chimpanzee was found to be 

 most sensitive to the disease ; it manifests primary 

 and secondary symptoms identical with those of 

 man. Lower monkeys, though less sensitive, also 

 contract syphilis but generally only show primary 

 characteristic manifestations. The possibility of 

 rapidly provoking in apes, even of the inferior kinds, 

 syphilitic lesions similar to those of man has a very 

 great importance, for it provides a sure means of 

 diagnosis in doubtful human cases. Owing to the 

 liability of apes to contract syphilis, experimental 

 vaccination and serotherapy could be attempted on 

 them ; but, though these experiments were sometimes 

 encouraging, the results obtained were not constant 

 enough to justify their application to man. Thus, 

 it was found possible to attenuate the virus by 

 successive passages in certain lower apes, and yet, 

 though attenuated for the chimpanzee, it did not 

 confer upon him immunity against the active virus. 



In 1905, Schaudinn discovered the syphilitic tre- 

 ponema in man. By using this discoverer's method, 

 the same microbe was found in apes inoculated with 

 human virus, which confirmed the specific character 

 of the treponema. 



An observation was then made which was of great 

 importance on account of its consequences : it was 

 ascertained that the syphilitic microbe was absorbed 

 by the less mobile mononuclear phagocytes and re- 

 mained localised near the entrance point long enough 



