﻿462 ASHBTJRN AND CRAIG. 



and we are forced to the conclusion that it is extremely difficult, if not 

 impossible, to inoculate syphilis in the species of monkeys used in our 

 experiments (Cynomolgvs pliilippinensis Geoff.). This difficulty, com- 

 pared with the ease with which framboesia in transmitted to the same 

 species, speaks very strongly against the identity of the two diseases. 



Yaws and syphilis. — As is well known, the question of the relation of 

 yaws to syphilis has always excited much controversy, and Hutchinson's 

 theory that yaws is the original form of syphilis, the latter disease, as 

 we observe it to-day, being framboesia modified by passage through the 

 Caucasian race, still has many supporters. The discovery of an organ- 

 ism in yaws lesions indistinguishable morphologically from Treponema 

 pallidum, at first sight appeared to lend additional evidence to the claim 

 that yaws and syphilis are identical, but the experimental evidence al- 

 read} r at hand demonstrates that the lesions produced by Treponema 

 pertenuis differ greatly from those caused by Treponema pallidum, and 

 that infection with one of these organisms does not produce immunity 

 against the other. Treponema pertenuis and Treponema pallidum. axe, 

 therefore, distinct species, and the lesions produced by each are charac- 

 teristic and easily distinguished clinically, in uncomplicated eases. 



There is no room for doubt in our minds, after consulting the work 

 of other authors and investigators and our own clinical and experi- 

 mental experience, that yaws and syphilis are distinct diseases, our be- 

 lief being based upon the following facts : 



(a) The pleomorphism of the lesions of syphilis, the uniformity of 

 those of yaws. 



(b) The granulomata (yaws papules) are the primary lesions of yaws; 

 such lesions, if syphilitic, could only be secondary or tertiary. 



(c) The presence of the very peculiar and typical yellow cap, or 

 crust, covering the yaws lesions. 



(d) In infected regions every uncomplicated case of yaws, whether 

 in children or adults, presents the same characteristic lesion (the pap- 

 ule covered with a yellow crust.) If the disease were syphilitic a wider 

 variation in the type of the lesion would be observed. 



(e) The epidemic occurrence of yaws, especially among young chil- 

 dren, and the greater prevalence of the disease in children. 



(/) The absence of genital infections in any case observed by us. 



(g) The absence in yaws of such striking symptoms as loss of hair 

 and iritis. 



(h) The auto-inoculability of yaws, even when a general eruption is 

 present. 



(i) The ready inoculability of yaws into such a low type of monkey 

 as Cynomolgus pliilippinensis Geoff., and the negative result of the 

 inoculation of syphilis in this species of monkey. 



