YAWS AND SYPHILIS 289 
Pathological histology of yaws. It recently has been suggested that the com- 
parison of the histopathological conditions observed in yaws and syphilis may 
give more definite information regarding their differentiation. 
During the present expedition we were able to obtain pathological material 
for the histological study of these late lesions of treponemiasis. 
The tissues removed from the patients in which the clinical diagnosis was 
treponemiasis (to which we have also referred under the local name of n’gonde) 
were excised both from areas where the epidermis was preserved, as well as 
from the edges of the ulcerative lesions. The margins of the ulcers were fre- 


Nos. 212, 213. — N’gonde (treponemiasis), Case 222 
quently thickened and hard and infiltrated. In some instances the bases of 
them were dirty and showed necrotic shreds, but more commonly they were 
flattened and clean and covered with granulations. The edges were often 
sharp and sloping, but sometimes were undermined. The ulcerating lesions 
were frequently more or less irregular in outline and had often become confluent. 
In other instances they were separated by retained skin or by retracting scar 
tissue. Many of the scars about the ulcerative lesions were thick and furrowed. 
Some of the shallow depressed scars were pink in color, while others retained 
no visible pigment and still others were often even more deeply pigmented. 
Nodular lesions, both subcutaneous and of infiltrated skin, were also removed. 
Many of the lesions resembled gummata of the skin, and among them different 
