648 



INFECTION AND IMMUNITY. 



from Monkey 



to Monkey, 



great abundance. In tertiary syphilis the lesions 

 contain only a few organisms. Those present are 

 most numerous in the tissues surrounding the 

 necrotic center. 



Experiment* It occurred to Metchnikoff and Roux as it had 

 occurred to others that the monkey, particularly 

 the higher species (chimpanzees), should on ac- 

 count of their biologic proximity to man, be the 

 most suitable animal for the production of experi- 

 mental syphilis. Attention has already been called 

 to this proximity as indicated by the reaction of 

 serum precipitins. 



Their first inoculation was performed on a fe- 



, . . 



male chimpanzee, virus irom a primary lesion and 

 from mucous patches being introduced by means 

 of scarification into the prepuce of the clitoris and 

 into the skin of the eyebrow. The wounds healed, 

 and twenty-six days after inoculation a vesicle 

 which soon was surrounded by induration appeared 

 on the prepuce. This lesion was pronounced a typi- 

 cal hard chancre by eminent dermatologists and 

 syphilologists. With the appearance of the chan- 

 cre the inguinal lymph glands became enlarged, 

 and one month later a papular eruption appeared 

 on the thighs, abdomen and back. The papules 

 persisted for more than a month, and were still 

 discernible when the animal died several weeks 

 later of pneumococcus infection. Before this ani- 

 mal died a second chimpanzee was inoculated from 

 the primary and secondary lesions of the first ani- 

 mal, resulting in the development of primary le- 

 sions and of adenitis. Still another successful in- 

 oculation resulted in secondary lesions with the 

 formation of mucous plaques. These observers 

 have since performed many similar experiments 



