﻿TREPONEMA PERTENUIS CASTELLANI OF YAWS. 451 



used in two ways, plain and heated to 60° C. for thirty minutes to destroy 

 complement. In none of these media did we obtain any growth of the 

 treponema., although bacteria developed in all. 



However, we did not have the opportunity to repeat these experiments, 

 and we are not convinced that cultivation of the treponema is impossible. 



PATHOGENESIS. 



It has been stated by different authors that yaws is inoculable on lower 

 animals, notably cats and monkeys, and that it is inoculable from person 

 to person. We have made no inoculation experiments on persons, and 

 none on lower animals other than monkeys (Cynomolgus philippinensis 

 Geoff.). Of these we inoculated five, using serum from the yaws of 

 three different patients. All five of the monkeys developed yaws lesions 

 of a sufficiently characteristic appearance to permit of diagnosis based 

 on that feature alone. 



In addition to this typical appearance we found Treponema pertenuis 

 in all of the lesions. The organisms did not differ in any demonstrable 

 way from those seen in serum from human lesions. In numbers, meas- 

 urements, staining reactions, shape and motion they were similar. 



However, the monkeys did not show the secondary lesions of a 

 generalized infection, nor could we, in the instance in which we tried it, 

 induce yaws in other mould's by inoculating them with the blood of 

 splenic juice of an infected animal. The yaws lesion did spread, and in 

 that way give rise to what might be termed secondary lesions, but this 

 was always by continuity and we observed no evidence to make us think 

 that it was ever through a general blood or lymph infection. 



BIOLOGICAL POSITION OF TREPONEMA PERTENUIS. 



We see no reason to doubt that the biological position of Treponema 

 pertenuis is as close to that of Treponema pallidum as one species may 

 be to another. The almost overwhelming weight of scientific opinion 

 at the present time seems to leave the latter organism where Schaudinn 

 placed it, among the Protozoa. 



However, its protozoal nature is not universally accepted, and probably 

 will not be for some time to come. Our opinion is that both organisms 

 are protozoal, but while so eminent a zoologist as Stiles (25) concedes to 

 others the right to regard pallidum as of vegetable nature, we feel that 

 we may safely grant the same latitude in respect to Treponema pertenuis. 

 What we believe to be more immediately important and more easily 

 determinable are the following propositions : 



First. That Treponema pertenuis is constantly found in the serum 

 from vaws lesions. 



