﻿TREPONEMA PERTENUIS CASTELLANI OF YAWS. 461 



natural, as in human infection, or experimental, as in the infection of 

 animals. 



Reinfection. — In only one instance [Monkey No. 2 (3071)] have we 

 attempted to reinfect a monkey that had recovered from framboesia, and 

 in this animal the reinoculation of human yaws serum resulted nega- 

 tively. 



Inoculation from monkey to monkey. — In one instance [Monkey No. 

 8 (3111)] we attempted to inoculate a monkey with the serum from a 

 well-marked lesion occurring in another animal of the same species, but 

 unfortunately the inoculated animal died in nineteen days, before the 

 probable period of incubation had expired. In view of the results of 

 Neisser, Baermann and Halberstadter, who obtained only one successful 

 result from the inoculation of seven monkeys with the serum of infected 

 animals, it is obvious that no conclusions can be drawn from our single 

 experiment. 



Inoculation of blood and splenic pulp. — In order to determine whether 

 framboesia, as observed in infected animals, is a general or local disease 

 we inoculated one monkey [No. 6 (3109)] with blood from the heart 

 of an animal infected with yaws, and another [No. 7 (3110)] with 

 splenic pulp from the same animal. No results followed these inoc- 

 ulations, but we do not consider that the experiments prove anything 

 as Neisser, Baermann and Halberstadter obtained only negative results 

 in six monkeys inoculated with splenic pulp and with a mixture of 

 splenic juice, bone marrow and mesenteric glands and only one positive 

 result in three animals inoculated with bone marrow. We did not at- 

 tempt the inoculation of bone marrow, but in view of the fact, that of 

 the nine animals injected by the investigators mentioned, the only 

 positive result was obtained by the inoculation of this substance, we feel 

 that our negative result with the blood and splenic pulp does not justify 

 us in drawing a definite conclusion as to the production of the disease in 

 this manner. 



Inoculation of yaws and syphilis. — Both Castellani(32) and Neisser 

 and his co-workers appear to have proved conclusively that monkeys 

 which have recovered from yaws are susceptible to syphilis. We have 

 endeavored to repeat their experiments, but have failed to produce 

 syphilis either in monkeys which have recovered from yaws or in those 

 that have never suffered from the disease. 



As shown in the protocols of our experiments, we inoculated two 

 animals, Monkey No. 1 (3070) and Monkey No. 4 (3073), both of 

 which had recovered from well-marked yaws lessions, with serum from 

 a chancre containing at the time of inoculation numerous examples of 

 Treponema pallidum. As controls we inoculated two healthy animals 

 with serum from the same case. At the present time, two months after 

 inoculation, none of these monkeys has developed syphilitic lesions, 



