﻿TREPONEMA PERTENUIS CASTELLANI OP YAWS. 463 



(_/') The fact, as proved by Neisser, Baermann, and Halberstadter, and 

 by Castellani, that monkeys susceptible to both yaws and syphilis can 

 be infected with both, no immunity being conferred against the one by 

 an attack of the other. 2 



(Jc) The fact,, as proved by Charlouis (33) and Powell (34), that 

 patients suffering from yaws can be infected with syphilis. 



GENERAL CONCLUSIONS. 



As a result of our observations, both clinical and experimental, we 

 believe that we are justified in drawing the following conclusions : 



1. That Treponema pertenuis is the cause of yaws. 



2. That Treponema pertenuis is constantly present in the serum from 

 yaws lesions. 



3. That the variations in the morphology of Treponema pertenuis are 

 explainable by the deformities produced during the preparation of the 

 serum for examination. 



4. That Treponema pertenuis and Treponema pallidum can be dif- 

 ferentiated by the results obtained from the inoculation of monkeys. 



5. That the inoculation of the serum from human yaws lesions con- 

 taining Treponema pertenuis causes yaws in monkeys and that the 

 organism can easily be demonstrated in the lesions of the infected 

 animals. 



6. That the length of the period of incubation in Cynomolgus philip- 

 pinensis Geoff, is approximately twenty days. 



7. That the duration of the inoculated disease in this species of 

 monkey varies from twenty-one to eighty-four days. 



8. That yaws and syphilis are distinct diseases. 



9. That Treponema pertenuis can be demonstrated in sections of yaws 

 papillomata by the Levaditi method. 



Castellani, in an article published in the Journal of Hygiene for July, 1907, 

 and only reaching here after the preceding paper had gone to the printer, draws 

 the following summary and conclusions : 



"1. Monkeys are susceptible to yaws. The skin eruption in the monkeys I 

 have experimented with (Semnopithecus priamus and Macacus pileatus) is, as 

 a rule, confined to the seat of inoculation, but the infection is general, as is 



2 On September 6, 1907, all of the experimental monkeys, except the two men- 

 tioned above as dead and monkey No. 2 (3071), which was killed, were examined 

 and none of them showed signs of either syphilis or yaws. One of the monkeys 

 utilized in the experiments detailed in this report [No. 2 (3071)] was killed 

 on July 22, 1907, because of the extension of the pyogenic ulcer on his brow to 

 the orbit. All of the others are still living on October 7, 1907, and one of them 

 [No. 11 (D)] has given birth to young. No one of them has shown signs or 

 symptoms of either yaws or syphilis since they were last noted in the report. 



