﻿TREPONEMA PEKTENUIS CASTELLANI OF YAWS. 459 



tubercle, was well illustrated. When fully developed the papules aver- 

 aged 1 centimeter in diameter. In one of our animals, Monkey No. 1 

 (3070), the lesion both upon the head and the abdomen was typical of 

 that variety of the disease described by Pierez(29), Scheube(30), Man- 

 son (31) and others as "ringworm yaws." The first lesion appeared 

 upon the abdomen and presented the appearance already described. 

 After a few days it was observed that in both the abdominal lesion and 

 that which had meanwhile appeared on the head, healing was occurring 

 at the center while the edges were covered with an elevated crust. At 

 this time the lesion resembled a ringworm infection so closely that we 

 made an examination for the fungus, with negative results. 



The lesion upon the head, when fully developed, measured about 2 

 centimeters in diameter and consisted of a perfect ring of raised, gran- 

 ulating tissue covered with the characteristic yellowish crust, and in- 

 closing the original site of the yaws papule, which had healed without 

 scar formation and but little pigmentation. Removal of the crust dis- 

 closed the usual moist, pink surface and an examination of the serum 

 exuding from it demonstrated the presence of Treponema pertenuis in 

 large numbers. A slight extension of this lesion occurred in the form 

 of a small, characteristic papule developing at its lower portion and 

 slightly involving the eyelid. 



The abdominal lesion enlarged rapidly and for some time presented 

 the appearance of a large yaws tubercle, markedly elevated and covered 

 with a mammillated yellow crust. Healing began at the center of the 

 tubercle and soon a typical, "ringworm" appearance was assumed but 

 here a very considerable invasion of the surrounding skin occurred, new 

 papules appeared at the periphery of the original lesion, so that eventually 

 nearly one-half of the surface of the abdomen was involved in the process. 

 The new lesions were easily demonstrated to be extensions, in direct con- 

 tinuity with preexisting ones and sound skin was never found separating 

 these lesions while in the active stage. Their progress answered perfectly 

 to the so-called secondary lesions described by Neisser, Baermann and 

 Halberstadter, but as we have stated, we can not regard them as an 

 evidence of a general infection and therefore as "secondary" in the sense 

 in which the term is used in connection with syphilis. 



After persisting for a varying period of time, the lesions of frambcesia 

 heal in the same manner as those occurring in man, the hypertrophied 

 papillae atrophy, the crust covering the papilloma shrivels up and falls 

 off, and a slightly discolored, but apparently sound area of skin, devoid 

 of hair, marks their former site. After a few days the hair again grows 

 and it becomes practically impossible to discover the point of the in- 

 oculation. As it is now nearly three months since our animals have 

 recovered from the infection, and as we have seen no evidence of a gen- 

 eralized secondary eruption, we believe we are justified in asserting that 



