TREPONEMATA 527 



the second stage; (3) tertiary stage, characterized by gumma-like 

 processes which may undergo deep ulceration. 



Morphology. Treponema pertenue is a very delicate, slender 

 spiral organism, measuring about 0.30 to 0.50 micron in diameter, 

 and from 6 to 18 microns in length. The ends of the organism are 

 frequently pointed, but one or both ends may be rounded, or, rarely, 

 somewhat swollen. There are usually from six to twenty spiral turns 

 in each organism. Blanchard 1 states that the organism possesses an 

 undulatory membrane, but the consensus of opinion is against this 

 view. Very delicate polar flagella, one at each end, have been demon- 

 strated by flagella stains. It will be observed that the size and arrange- 

 ment of the organism do not differ essentially from that of Treponema 

 pallidum. The organism fails to stain by ordinary methods, but the 

 morphology is well brought out by Giemsa's stain. Treponema per- 

 tenue may be demonstrated by the methods applicable for Treponema 

 pallidum. It has never been cultivated in artificial media. 



Specificity of Organism. Paulet 2 inoculated fourteen negroes with 

 the secretion from granulomata and all developed yaws, the initial 

 lesion appearing at the site of inoculation. There is a possibility that 

 these negroes might have been naturally infected, however. Charlouis 

 injected thirty-two Chinese prisoners with scrapings from the granulo- 

 mata of a case of yaws and twenty-eight developed the disease, the 

 primary lesion again appearing at the site of inoculation. This series 

 is suggestive, but not conclusive, because the possibility of natural 

 infection can not be ruled out. 



According to Castellani, 3 yaws and syphilis are distinct diseases, 

 because a native who had been inoculated successfully with yaws was 

 subsequently infected with material from a chancre; this resulted in 

 a typical attack of syphilis superimposed upon the yaws. In Ceylon 

 syphilis is not uncommonly observed in cases of yaws which are in 

 the secondary or tertiary stages. 



Pathogenesis. Animal. The disease may be transferred to monkeys 

 by direct inoculation. The organisms are found in the lesions. 



Human. The distribution of Treponema pertenue in the lesions 

 of yaws is somewhat different from that of Treponema pallidum in 

 syphilis. In the former the organisms are numerous in the spaces 

 between the papillary pegs of the malpighian layer of the epidermis, 



1 Arch. d. Parasit., 1906. 



2 Quoted by Castellani and Chalmers, Manual of Tropical Medicine. 



3 Loc. cit. 



