Conclusion and Summary 1. The yaws cases seen in Panama show a marked tendency to local and regional limitation of late pathology. 2. Compared with yaws in Haiti, this regional limitation in the Panama series is double that found among the Haitien cases. 3. The route of transmission of infection from the primary yaw to other parts of the skin surface can not be definitely traced in many instances but considerable evidence indicates an impetigo like spread, i.e., a mechanical transfer of infectious material over the body surface. 4. Undoubtedly transfer of the infection within the body is accomplished through the lymphatic system or general circulation in a small percentage of cases. 5. With but two exceptions all periosteal cases in the Panama group were caused by direct extension of the infection from over lying ulcers. 6. The strain of T. pertenue found in Panama is a much less virulent strain than that encountered in Haiti. 7. “Dryyaws” eruption, either of the ringworm or non-progressive papular type, probably accounts for the long quiescent periods so frequently seen in cases of late yaws. 8. “Dryyaws” on the skin around joint protuberances probably indicates the portal of infection which later manifests itself as a juxta articular node. 9. It is believed that very rarely yaws may be the accidental etiological factor in aneurysm and cerebral thrombosis or cerebral hemorrhage of young adults.