280 The Philippine Journal of Science 1923 



more compact state of the epidermis with its active hyperkera- 

 tosis. Certainly the exchange of fluids appears much less than 

 in the stage of continuous serous exudation. The fact that the 

 older lesions succumb less readily to treatment than the exud- 

 ing early ones is not altogether due to the established histological 

 changes in the former. It would seem an advisable precaution 

 to continue treatment until healing of such lesions is complete. 



SUMMARY 



1. Treponema pertenue has been demonstrated by Levaditi's 

 method in abundance in early yaws, not only within the 

 thickened epidermis as heretofore observed, but also within 

 perivascular connective tissue of the papillae. 



2. The lesions studied indicate that the secondary yaw begins 

 with a localization of treponemata, from the blood, in certain 

 papillae, and from such points the organisms infect the epider- 

 mis, where conditions become more favorable for their growth. 



3. Within forty hours after the injection of a therapeutic 

 dose of neosalvarsan all treponemata demonstrable by Levaditi's 

 method had disappeared from early yaws. 



4. The remarkably rapid healing of secondary cutaneous 

 lesions after injection of neosalvarsan consists essentially in 

 an almost immediate suppression of acute exudation, and the 

 removal of excessive fluid and cellular exudate by surface evap- 

 oration, by absorption, and by phagocytosis. The thickened 

 epidermis quickly resumes normal differentiation with hyper- 

 keratosis for a while until the epithelial layer becomes again of 

 normal width and rapidity of growth. 



5. It seems probable that neosalvarsan is destructive of poly- 

 morphonuclear leucocytes in the lesions, and this may favor 

 the rapid disintegration of treponemata. 



6. The older secondary nodular lesions have a more-perma- 

 nent architecture, heal less rapidly, and probably offer greater 

 protection to treponemata; consequently, they require more 

 care in effecting a complete cure. 



REFERENCES 



1. Castellani, A. Brit. Med. Journ. 2 (1905) 1280. 



2. Castellani, A. Journ. Cut. Dis. 26 (1908) 151. 



3. Charlouis, M. Vierteljahresschr. (Archiv) f. Derm. u. Syph. 13 (1881) 



