﻿4(50 - ASHBURN AND CRAIG. 



in the species of monkey we used, a general eruption of yaws does not 

 occur after experimental inoculation. While the lesions of frambcesia 

 are undoubtedly modified somewhat in the monkeys of the low type 

 used in our work, they are yet so characteristic that we believe, from 

 their appearance alone, a clinical diagnosis could be made even in 

 the mildest case of infection we have observed, while in the more severe 

 infections, such as Monkey No. 1 (3070), the nature of the lesion was 

 apparent at a glance. It is probable that if higher species of apes were 

 used, the lesions would be much more pronounced and a generalized 

 eruption of yaws tubercles might occur. 



Examination for Treponema pertenuis. — We have examined the lesions 

 in all of our sucessfully inoculated animals for Treponema pertenuis and 

 have repeatedly demonstrated its presence in every case, without any spe- 

 cial difficulty. The organisms occurred usually in the very earliest stage 

 of growth of the yaws papule and persisted until the lesion had nearly 

 healed, being most numerous during the active growth of the papule and 

 decreasing in number as the healing process advanced. As we have stated, 

 the treponema occurring in the lesions in monkeys did not differ in any 

 particular from the ones found in the serum from the lesions in man. 

 In most instances no other spiroehsetse were observed in the preparation, 

 although, in one or two cases, organisms corresponding to the type 

 of 8. refrigens were observed, but these were very rare. As in man, 

 the lesions covered with crust showed the treponema unmixed with other 

 spirochgetae, while in those in which the crust had been removed, for 

 instance by scratching, thus allowing secondary infections to occur, 

 organisms corresponding to the types described by Castellani were infre- 

 quently observed. 



Serum from the lesions in some of our inoculated animals was col- 

 lected in capillary tubes and kept for varying periods of time. Apparent 

 multiplication of Treponema pertenuis occurred in some, and the organ- 

 isms remained motile for several days. In the material so collected the 

 organisms occurred singly, in pairs, or in clumps. Agglutination and 

 apparent longitudinal division were also observed in the serum from the 

 lesions in these animals. 



We consider the constant presence of Treponema pertenuis in the ex- 

 perimental lesions of yaws in monkeys, produced by the inoculation from 

 the lesions in man, of serum containing them and their absence in 

 other conditions, to be conclusive proof of their etiological relationship 

 to frambcesia. If we add to this the fact that as the lesions heal, the 

 treponema gradually disappear and the further fact, as proved by the 

 case of Monkey No. 2 (3071), that the organisms can not be found in 

 pyogenic ulcerations even when inoculated, unless frambcesia be induced, 

 it appears to us that the evidence is complete. Treponema pertenuis is 

 found constantly and only in the lesions of frambcesia, whether they are 



